2个回答
展开全部
1.(x-1.5-1)/4=(x-1.5+1)/5
5(x-2.5)=4(x-0.5)
x=-2+12.5
x=10.5
2.l+300=30v
300-l=10v
v=15m/s
l=150m
3.80x+80y=400
80y-80x=400
所以x=0 y=5
4.[x-4*(18-x-y)/60]/4=(18-y)/60
y/4=(18-x)/60+(18-x-y)/60
所以x=2 y=2
5.x=4y
3x+11-x-y=25
x=8
y=2
6.(x-2)12=8x
x=6
7.x+y=4/5.2
x-y=4/6.5
解得:x=9/13,y=1/13
8.5*(1/3)+5*X=15*X
x=1/6
9.(1/3)x/12=(1/3)x/[12*(5/4)]+1
化简得:
(5/3)x=(4/3)x+60
(1/3)x=60
x=180
10.2X+5X=14000
7X=14000
X=2000
2X=4000
5X=10000
11. x+(35-20)*1.5%x=1323 x=1080
12 . 2x-10.3x=15
13 . 0.52x-(1-0.52)x=80
14 . x/2+3x/2=7
15 . 3x+7=32-2x
16 . 3x+5(138-x)=540
17 . 3x-7(x-1)=3-2(x+3)
18 . 18x+3x-3=18-2(2x-1)
19 . 3(20-y)=6y-4(y-11)
20. -(x/4-1)=5
21. 3[4(5y-1)-8]=6
22.3X+189=521
23.4Y+119=22
24.3X*189=5
25.8Z/6=458
26.3X+77=59
27.4Y-6985=81
28.87X*13=5
29.7Z/93=41
30.15X+863-65X=54
31.58Y*55=27489
32.3X+18=52 x=34/3
33.4Y+11=22 y=11/4
34.3X*9=5 x=5/27
35.8Z/6=48 z=36
36.3X+7=59 x=52/3
37.4Y-69=81 y=75/4
38.8X*6=5 x=5/48
39.7Z/9=4 y=63/7
40.15X+8-5X=54 x=4.6
41.5Y*5=27 y=27/40
42.8x+2=10 x=1
43.x*8=88 x=11
44.y-90=1 y=91
45.2x-98=2 x=50
46.6x*6=12 x=1/3
47.5-6=5x x=-1/5
48.6*x=42 x=7
49.55-y=33 y=22
50.11*3x=60 x=20/11
51.8-y=2 y=-6
52.x+2=3
53.x+32=33
54.x+6=18
55.4+x=47
56.19-x=8
57.98-x=13
58.66-x=10
59.5x=10
60.3x=27
61.7x=7
62.8x=8
63.9x=9
64.10x=100
65.66x=660
66.7x=49
67.2x=4
68.3x=9
69.4x=16
70.5x=25
71.6x=36
72.8x=64
73.9x=81
74.10x=100
75.11x=121
76.12x=144
77.13x=169
78.14x=196
79.15x=225
80.16x=256
81.17x=289
82.18x=324
83.19x=361
84.20x=400
85.21x=441
86.22x=484
87.111x=12321
88.1111x=1234321
89.11111x=123454321
90.111111x=12345654321
91.46/x=23
92.64/x=8
93.99/x=11
94.1235467564x=0
95.2x+1= -2+x
96.4x-3(20-x)=3
97.-2(x-1)=4
98.3X+189=521
99.4Y+119=22 5
100.3X+77=59
101.4Y-6985=81
102.X=0.1
103.5X=55.5
104.Y=50-85
105.3y-y=3+4,2y=7,y=3.5
106.0.4x+0.1x=2-3;0.5x=-1,x=-2
107.5x+15-2x-2=10,3x=-3,x=-1
108.[73X+78(100-X)]除以100=75.4
解:方程两边同乘以100,得73x+78(100-x)=7540
去括号,得 73x+7800-78x=7540
移项,得 73x-78x=7540-7800
合并同类项,得 -5x=-260
系数化为1,得 x=52
109.9x-120=5(x-8)
解这个方程,得 x=20
110.4x/5-30+10=3/4(x-10)
解这个方程,得 x=250
111.x+100=10x+1-414
解这个方程,得 x=57
112. x(1+20%)=9600
y(1-20%)=9600
解得 x=8000
y=12000
113.15(x-1)-8(3x+2)
=2-30(x-1)
21x=63
x=3
114.5x+4.5(103-x)=486
解得x=45
115.8-0.5x=4.5.
解这个方程,得x=7
116.180x=80x+80×5,
移项,得100x=400.
系数化为1,得x=4.
117.1.6+1+x+1=2(3-2×0.5)
解得x=0.4,
118.3x=9
119. 5x=110
120.7(5+6)-x=0
121.3x/5=45x
122.X-480-(X-480)×0.375=5/12 X
x-480-(3/8x-180)=5/12x
x-480-3/8x+180=5/12x
x-3/8x-5/12x=480-180
5/24x=300
x=1440
123.20x+30*2x+70*(47-3x)=2120
20x+60x+3290-210x=2120
3290-120x=2120
x=9
124.3X/5 +10= 10/7
125.2x+5=9
126.10x-5(15-x)=60
x=9
127.8x=6*40/60+8
x=3/2
128.20-X=5 X=15
129.7(2x-1)-3(4x-1)=4(3x+2)-1
解 14x-7-12x+3=12x+8-1
14x-12x-12x=8-1+7-3 -10x=11 x=-1
130.2(x-2)+2=x+1
131.2(x-2)-3(4x-1)=9(1-x)
132.11x+64-2x=100-9x
133.7(2x-1)-3*(4x-1)=4(3x+2)-1
134.(5x+1)+(1-x)=(9x+1)+(1-3x)
135.(x-6)*7=2x
136.x+(4/5)x-30=x-10+(3/4)(x-10)
137.x-x/4=x-72
138.1800=60[x-(30-x)]
139.14.59+x-25.31=0
x=10.72
140.x-48.32+78.51=80
x=49.81
141.820-16x=45.5×8
x=28.5
142.(x-6)×7=2x
x=8.4
143.3x+x=18
x=4.5
144.0.8x+2.2=6.6
x= 11
145.12.5-3x=6.5
x=2
146.1.2(x-0.64)=0.54
x=1.09
147.x+12.5=3.5x
x=5
148.8x-22.8=1.2
x=3
149.[(x-140)*0.57+140*0.43]/x=0.5
0.57x-79.8+60.2=0.5x
0.07x=19.6
x=280
150.(X+22)/(8X-22)=2/5
5*(X+22)=2*(8X-22)
5X+110=16X-44
11X=154
X=14
151.90%*(1+x%)=1
解得: x=1/9
152.(1-10%)X+(1+5%)(100-X)=100(1+2%)
结果X=20元
153.X+4/5X-30=X-10+3/4(X-10)
X=250
154.x-(x/4)=x-72
x=288
155.180*2=60[X-(30-X)]
X=18
156.1-X/3=2[1-3X/8]
X=2.4
157.0.4(x-0.2)+1.5=0.7x-0.38
x=6
158.30x-10(10-x)=100
x=5
159.4(x+2)=5(x-2)
x=18
160.120-4(x+5)=25
x=18.75
161.15x+863-65x=54
x=16.18
162.3(x-2)+1=x-(2x-1)
x=3/2
163.11x+64-2x=100-9x
x=2
164.5x+6+x=12 x=2
165.3y+(9-6)=33 y=10
166.3x+20=4x-25 x=45
167.6x+6(x-2000)=150000 x=13500
4.7x-(5x-5y)-y=______.
5.23a3bc2-15ab2c+8abc-24a3bc2-8abc=______.
6.-7x2+6x+13x2-4x-5x2=______.
7.2y+(-2y+5)-(3y+2)=______.
11.(2x2-3xy+4y2)+(x2+2xy-3y2)=______.
12.2a-(3a-2b+2)+(3a-4b-1)=______.
13.-6x2-7x2+15x2-2x2=______.
14.2x-(x+3y)-(-x-y)-(x-y)=______.
16.2x+2y-[3x-2(x-y)]=______.
17.5-(1-x)-1-(x-1)=______.
18.( )+(4xy+7x2-y2)=10x2-xy.
19.(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
21.已知A=x3-2x2+x-4,B=2x3-5x+3,计算A+B=______.
22.已知A=x3-2x2+x-4,B=2x3-5x+3,计算A-B=______.
23.若a=-0.2,b=0.5,代数式-(|a2b|-|ab2|)的值为______.
25.一个多项式减去3m4-m3-2m+5得-2m4-3m3-2m2-1,那么这个多项式等于______.
26.-(2x2-y2)-[2y2-(x2+2xy)]=______.
27.若-3a3b2与5ax-1by+2是同类项,则x=______,y=______.
28.(-y+6+3y4-y3)-(2y2-3y3+y4-7)=______.
29.化简代数式4x2-[7x2-5x-3(1-2x+x2)]的结果是______.
30.2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( ).
31.3a-(2a-3b)+3(a-2b)-b=______.
32.化简代数式x-[y-2x-(x+y)]等于______.
33.[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1.
34.3x-[y-(2x+y)]=______.
35.化简|1-x+y|-|x-y|(其中x<0,y>0)等于______.
36.已知x≤y,x+y-|x-y|=______.
37.已知x<0,y<0,化简|x+y|-|5-x-y|=______.
38.4a2n-an-(3an-2a2n)=______.
39.若一个多项式加上-3x2y+2x2-3xy-4得
2x2y+3xy2-x2+2xy,
则这个多项式为______.
40.-5xm-xm-(-7xm)+(-3xm)=______.
41.当a=-1,b=-2时,
[a-(b-c)]-[-b-(-c-a)]=______.
43.当a=-1,b=1,c=-1时,
-[b-2(-5a)]-(-3b+5c)=______.
44.-2(3x+z)-(-6x)+(-5y+3z)=______.
45.-5an-an+1-(-7an+1)+(-3an)=______.
46.3a-(2a-4b-6c)+3(-2c+2b)=______.
48.9a2+[7a2-2a-(-a2+3a)]=______.
50.当2y-x=5时,5(x-2y)2-3(-x+2y)-100=______.
(二)选择
[ ]
A.2;
B.-2;
C.-10;
D.-6.
52.下列各式中计算结果为-7x-5x2+6x3的是 [ ]
A.3x-(5x2+6x3-10x);
B.3x-(5x2+6x3+10x);
C.3x-(5x2-6x3+10x);
D.3x-(5x2-6x3-10x).
53.把(-x-y)+3(x+y)-5(x+y)合并同类项得 [ ]
A.(x-y)-2(x+y);
B.-3(x+y);
C.(-x-y)-2(x+y);
D.3(x+y).
54.2a-[3b-5a-(2a-7b)]等于 [ ]
A.-7a+10b;
B.5a+4b;
C.-a-4b;
D.9a-10b.
55.减去-3m等于5m2-3m-5的代数式是 [ ]
A.5(m2-1);
B.5m2-6m-5;
C.5(m2+1);
D.-(5m2+6m-5).
56.将多项式2ab-9a2-5ab-4a2中的同类项分别结合在一起,应为 [ ]
A.(9a2-4a2)+(-2ab-5ab);
B.(9a2+4a2)-(2ab-5ab);
C.(9a2-4a2)-(2ab+5ab);
D.(9a2-4a2)+(2ab-5ab).
57.当a=2,b=1时,-a2b+3ba2-(-2a2b)等于 [ ]
A.20;
B.24;
C.0;
D.16.
中,正确的选择是 [ ]
A.没有同类项;
B.(2)与(4)是同类项;
C.(2)与(5)是同类项;
D.(2)与(4)不是同类项.
59.若A和B均为五次多项式,则A-B一定是 [ ]
A.十次多项式;
B.零次多项式;
C.次数不高于五次的多项式;
D.次数低于五次的多项式.
60.-{[-(x+y)]}+{-[(x+y)]}等于 [ ]
A.0;
B.-2y;
C.x+y;
D.-2x-2y.
61.若A=3x2-5x+2,B=3x2-5x+6,则A与B的大小是
[ ]
A.A>B;
B.A=B;
C.A<B;
D.无法确定.
62.当m=-1时,-2m2-[-4m2+(-m2)]等于 [ ]
A.-7;
B.3;
C.1;
D.2.
63.当m=2,n=1时,多项式-m-[-(2m-3n)]+[-(-3m)-4n]等于 [ ]
A.1;
B.9;
C.3;
D.5.
[ ]
65.-5an-an-(-7an)+(-3an)等于 [ ]
A.-16an;
B.-16;
C.-2an;
D.-2.
66.(5a-3b)-3(a2-2b)等于 [ ]
A.3a2+5a+3b;
B.2a2+3b;
C.2a3-b2;
D.-3a2+5a-5b.
67.x3-5x2-4x+9等于 [ ]
A.(x3-5x2)-(-4x+9);
B.x3-5x2-(4x+9);
C.-(-x3+5x2)-(4x-9);
D.x3+9-(5x2-4x).
[ ]
69.4x2y-5xy2的结果应为 [ ]
A.-x2y;
B.-1;
C.-x2y2;
D.以上答案都不对.
(三)化简
70.(4x2-8x+5)-(x3+3x2-6x+2).
72.(0.3x3-x2y+xy2-y3)-(-0.5x3-x2y+0.3xy2).
73.-{2a2b-[3abc-(4ab2-a2b)]}.
74.(5a2b+3a2b2-ab2)-(-2ab2+3a2b2+a2b).
75.(x2-2y2-z2)-(-y2+3x2-z2)+(5x2-y2+2z2).
76.(3a6-a4+2a5-4a3-1)-(2-a+a3-a5-a4).
77.(4a-2b-c)-5a-[8b-2c-(a+b)].
78.(2m-3n)-(3m-2n)+(5n+m).
79.(3a2-4ab-5b2)-(2b2-5a2+2ab)-(-6ab).
80.xy-(2xy-3z)+(3xy-4z).
81.(-3x3+2x2-5x+1)-(5-6x-x2+x3).
83.3x-(2x-4y-6x)+3(-2z+2y).
84.(-x2+4+3x4-x3)-(x2+2x-x4-5).
85.若A=5a2-2ab+3b2,B=-2b2+3ab-a2,计算A+B.
86.已知A=3a2-5a-12,B=2a2+3a-4,求2(A-B).
87.2m-{-3n+[-4m-(3m-n)]}.
88.5m2n+(-2m2n)+2mn2-(+m2n).
89.4(x-y+z)-2(x+y-z)-3(-x-y-z).
90.2(x2-2xy+y2-3)+(-x2+y2)-(x2+2xy+y2).
92.2(a2-ab-b2)-3(4a-2b)+2(7a2-4ab+b2).
94.4x-2(x-3)-3[x-3(4-2x)+8].
(四)将下列各式先化简,再求值
97.已知a+b=2,a-b=-1,求3(a+b)2(a-b)2-5(a+b)2×(a-b)2的值.
98.已知A=a2+2b2-3c2,B=-b2-2c2+3a2,C=c2+2a2-3b2,求(A-B)+C.
99.求(3x2y-2xy2)-(xy2-2x2y),其中x=-1,y=2.
101.已知|x+1|+(y-2)2=0,求代数式5(2x-y)-3(x-4y)的值.
106.当P=a2+2ab+b2,Q=a2-2ab-b2时,求P-[Q-2P-(P-Q)].
107.求2x2-{-3x+5+[4x2-(3x2-x-1)]}的值,其中x=-3.
110.当x=-2,y=-1,z=3时,求5xyz-{2x2y-[3xyz-(4xy2-x2y)]}的值.
113.已知A=x3-5x2,B=x2-6x+3,求A-3(-2B).
(五)综合练习
115.去括号:{-[-(a+b)]}-{-[-(a-b)]}.
116.去括号:-[-(-x)-y]-[+(-y)-(+x)].
117.已知A=x3+6x-9,B=-x3-2x2+4x-6,计算2A-3B,并把结果放在前面带“-”号的括号内.
118.计算下式,并把结果放在前面带“-”号的括号内:
(-7y2)+(-4y)-(-y2)-(+5y)+(-8y2)+(+3y).
119.去括号、合并同类项,将结果按x的升幂排列,并把后三项放在带有“-”号的括号内:
120.不改变下式的值,将其中各括号前的符号都变成相反的符号:(x3+3x2)-(3x2y-7xy)+(2y3-3y2).
121.把多项式4x2y-2xy2+4xy+6-x2y2+x3-y2的三次项放在前面带有“-”号的括号内,二次项放在前面带有“+”号的括号内,四次项和常数项放在前面带有“-”号的括号内.
122.把下列多项式的括号去掉,合并同类项,并将其各项放在前面带有“-”号的括号内,再求2x-2[3x-(5x2-2x+1)]-4x2的值,其中x=-1.
123.合并同类项:
7x-1.3z-4.7-3.2x-y+2.1z+5-0.1y.
124.合并同类项:5m2n+5mn2-mn+3m2n-6mn2-8mn.
126.去括号,合并同类项:
(1)(m+1)-(-n+m);
(2)4m-[5m-(2m-1)].
127.化简:2x2-{-3x-[4x2-(3x2-x)+(x-x2)]}.
128.化简:-(7x-y-2z)-{[4x-(x-y-z)-3x+z]-x}.
129.计算:(+3a)+(-5a)+(-7a)+(-31a)-(+4a)-(-8a).
130.化简:a3-(a2-a)+(a2-a+1)-(1-a4+a3).
131.将x2-8x+2x3-13x2-2x-2x3+3先合并同类项,再求值,其中x=-4.
132.在括号内填上适当的项:[( )-9y+( )]+2y2+3y-4=11y2-( )+13.
133.在括号内填上适当的项:
(-x+y+z)(x+y-z)=[y-( )][y+( )].
134.在括号内填上适当的项:
(3x2+xy-7y2)-( )=y2-2xy-x2.
135.在括号内填上适当的项:
(1)x2-xy+y-1=x2-( );
(2)[( )+6x-7]-[4x2+( )-( )]=x2-2x+1.
136.计算4x2-3[x+4(1-x)-x2]-2(4x2-1)的值.
137.化简:
138.用竖式计算
(-x+5+2x4-6x3)-(3x4+2x2-3x3-7).
139.已知A=11x3+8x2-6x+2,B=7x3-x2+x+3,求2(3A-2B).
140.已知A=x3-5x2,B=x3-11x+6,C=4x-3,求
(1)A-B-C;
(2)(A-B-C)-(A-B+C).
141.已知A=3x2-4x3,B=x3-5x2+2,计算
(1)A+B;
(2)B-A.
142.已知x<-4,化简|-x|+|x+4|-|x-4|.
146.求两代数式-1.56a+3.2a3-0.47,2.27a3-0.02a2+4.03a+0.53的差与6-0.15a+3.24a2+5.07a3的和.
-0.3,y=-0.2.
150.已知(x-3)2+|y+1|+z2=0
5(x-2.5)=4(x-0.5)
x=-2+12.5
x=10.5
2.l+300=30v
300-l=10v
v=15m/s
l=150m
3.80x+80y=400
80y-80x=400
所以x=0 y=5
4.[x-4*(18-x-y)/60]/4=(18-y)/60
y/4=(18-x)/60+(18-x-y)/60
所以x=2 y=2
5.x=4y
3x+11-x-y=25
x=8
y=2
6.(x-2)12=8x
x=6
7.x+y=4/5.2
x-y=4/6.5
解得:x=9/13,y=1/13
8.5*(1/3)+5*X=15*X
x=1/6
9.(1/3)x/12=(1/3)x/[12*(5/4)]+1
化简得:
(5/3)x=(4/3)x+60
(1/3)x=60
x=180
10.2X+5X=14000
7X=14000
X=2000
2X=4000
5X=10000
11. x+(35-20)*1.5%x=1323 x=1080
12 . 2x-10.3x=15
13 . 0.52x-(1-0.52)x=80
14 . x/2+3x/2=7
15 . 3x+7=32-2x
16 . 3x+5(138-x)=540
17 . 3x-7(x-1)=3-2(x+3)
18 . 18x+3x-3=18-2(2x-1)
19 . 3(20-y)=6y-4(y-11)
20. -(x/4-1)=5
21. 3[4(5y-1)-8]=6
22.3X+189=521
23.4Y+119=22
24.3X*189=5
25.8Z/6=458
26.3X+77=59
27.4Y-6985=81
28.87X*13=5
29.7Z/93=41
30.15X+863-65X=54
31.58Y*55=27489
32.3X+18=52 x=34/3
33.4Y+11=22 y=11/4
34.3X*9=5 x=5/27
35.8Z/6=48 z=36
36.3X+7=59 x=52/3
37.4Y-69=81 y=75/4
38.8X*6=5 x=5/48
39.7Z/9=4 y=63/7
40.15X+8-5X=54 x=4.6
41.5Y*5=27 y=27/40
42.8x+2=10 x=1
43.x*8=88 x=11
44.y-90=1 y=91
45.2x-98=2 x=50
46.6x*6=12 x=1/3
47.5-6=5x x=-1/5
48.6*x=42 x=7
49.55-y=33 y=22
50.11*3x=60 x=20/11
51.8-y=2 y=-6
52.x+2=3
53.x+32=33
54.x+6=18
55.4+x=47
56.19-x=8
57.98-x=13
58.66-x=10
59.5x=10
60.3x=27
61.7x=7
62.8x=8
63.9x=9
64.10x=100
65.66x=660
66.7x=49
67.2x=4
68.3x=9
69.4x=16
70.5x=25
71.6x=36
72.8x=64
73.9x=81
74.10x=100
75.11x=121
76.12x=144
77.13x=169
78.14x=196
79.15x=225
80.16x=256
81.17x=289
82.18x=324
83.19x=361
84.20x=400
85.21x=441
86.22x=484
87.111x=12321
88.1111x=1234321
89.11111x=123454321
90.111111x=12345654321
91.46/x=23
92.64/x=8
93.99/x=11
94.1235467564x=0
95.2x+1= -2+x
96.4x-3(20-x)=3
97.-2(x-1)=4
98.3X+189=521
99.4Y+119=22 5
100.3X+77=59
101.4Y-6985=81
102.X=0.1
103.5X=55.5
104.Y=50-85
105.3y-y=3+4,2y=7,y=3.5
106.0.4x+0.1x=2-3;0.5x=-1,x=-2
107.5x+15-2x-2=10,3x=-3,x=-1
108.[73X+78(100-X)]除以100=75.4
解:方程两边同乘以100,得73x+78(100-x)=7540
去括号,得 73x+7800-78x=7540
移项,得 73x-78x=7540-7800
合并同类项,得 -5x=-260
系数化为1,得 x=52
109.9x-120=5(x-8)
解这个方程,得 x=20
110.4x/5-30+10=3/4(x-10)
解这个方程,得 x=250
111.x+100=10x+1-414
解这个方程,得 x=57
112. x(1+20%)=9600
y(1-20%)=9600
解得 x=8000
y=12000
113.15(x-1)-8(3x+2)
=2-30(x-1)
21x=63
x=3
114.5x+4.5(103-x)=486
解得x=45
115.8-0.5x=4.5.
解这个方程,得x=7
116.180x=80x+80×5,
移项,得100x=400.
系数化为1,得x=4.
117.1.6+1+x+1=2(3-2×0.5)
解得x=0.4,
118.3x=9
119. 5x=110
120.7(5+6)-x=0
121.3x/5=45x
122.X-480-(X-480)×0.375=5/12 X
x-480-(3/8x-180)=5/12x
x-480-3/8x+180=5/12x
x-3/8x-5/12x=480-180
5/24x=300
x=1440
123.20x+30*2x+70*(47-3x)=2120
20x+60x+3290-210x=2120
3290-120x=2120
x=9
124.3X/5 +10= 10/7
125.2x+5=9
126.10x-5(15-x)=60
x=9
127.8x=6*40/60+8
x=3/2
128.20-X=5 X=15
129.7(2x-1)-3(4x-1)=4(3x+2)-1
解 14x-7-12x+3=12x+8-1
14x-12x-12x=8-1+7-3 -10x=11 x=-1
130.2(x-2)+2=x+1
131.2(x-2)-3(4x-1)=9(1-x)
132.11x+64-2x=100-9x
133.7(2x-1)-3*(4x-1)=4(3x+2)-1
134.(5x+1)+(1-x)=(9x+1)+(1-3x)
135.(x-6)*7=2x
136.x+(4/5)x-30=x-10+(3/4)(x-10)
137.x-x/4=x-72
138.1800=60[x-(30-x)]
139.14.59+x-25.31=0
x=10.72
140.x-48.32+78.51=80
x=49.81
141.820-16x=45.5×8
x=28.5
142.(x-6)×7=2x
x=8.4
143.3x+x=18
x=4.5
144.0.8x+2.2=6.6
x= 11
145.12.5-3x=6.5
x=2
146.1.2(x-0.64)=0.54
x=1.09
147.x+12.5=3.5x
x=5
148.8x-22.8=1.2
x=3
149.[(x-140)*0.57+140*0.43]/x=0.5
0.57x-79.8+60.2=0.5x
0.07x=19.6
x=280
150.(X+22)/(8X-22)=2/5
5*(X+22)=2*(8X-22)
5X+110=16X-44
11X=154
X=14
151.90%*(1+x%)=1
解得: x=1/9
152.(1-10%)X+(1+5%)(100-X)=100(1+2%)
结果X=20元
153.X+4/5X-30=X-10+3/4(X-10)
X=250
154.x-(x/4)=x-72
x=288
155.180*2=60[X-(30-X)]
X=18
156.1-X/3=2[1-3X/8]
X=2.4
157.0.4(x-0.2)+1.5=0.7x-0.38
x=6
158.30x-10(10-x)=100
x=5
159.4(x+2)=5(x-2)
x=18
160.120-4(x+5)=25
x=18.75
161.15x+863-65x=54
x=16.18
162.3(x-2)+1=x-(2x-1)
x=3/2
163.11x+64-2x=100-9x
x=2
164.5x+6+x=12 x=2
165.3y+(9-6)=33 y=10
166.3x+20=4x-25 x=45
167.6x+6(x-2000)=150000 x=13500
4.7x-(5x-5y)-y=______.
5.23a3bc2-15ab2c+8abc-24a3bc2-8abc=______.
6.-7x2+6x+13x2-4x-5x2=______.
7.2y+(-2y+5)-(3y+2)=______.
11.(2x2-3xy+4y2)+(x2+2xy-3y2)=______.
12.2a-(3a-2b+2)+(3a-4b-1)=______.
13.-6x2-7x2+15x2-2x2=______.
14.2x-(x+3y)-(-x-y)-(x-y)=______.
16.2x+2y-[3x-2(x-y)]=______.
17.5-(1-x)-1-(x-1)=______.
18.( )+(4xy+7x2-y2)=10x2-xy.
19.(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
21.已知A=x3-2x2+x-4,B=2x3-5x+3,计算A+B=______.
22.已知A=x3-2x2+x-4,B=2x3-5x+3,计算A-B=______.
23.若a=-0.2,b=0.5,代数式-(|a2b|-|ab2|)的值为______.
25.一个多项式减去3m4-m3-2m+5得-2m4-3m3-2m2-1,那么这个多项式等于______.
26.-(2x2-y2)-[2y2-(x2+2xy)]=______.
27.若-3a3b2与5ax-1by+2是同类项,则x=______,y=______.
28.(-y+6+3y4-y3)-(2y2-3y3+y4-7)=______.
29.化简代数式4x2-[7x2-5x-3(1-2x+x2)]的结果是______.
30.2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( ).
31.3a-(2a-3b)+3(a-2b)-b=______.
32.化简代数式x-[y-2x-(x+y)]等于______.
33.[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1.
34.3x-[y-(2x+y)]=______.
35.化简|1-x+y|-|x-y|(其中x<0,y>0)等于______.
36.已知x≤y,x+y-|x-y|=______.
37.已知x<0,y<0,化简|x+y|-|5-x-y|=______.
38.4a2n-an-(3an-2a2n)=______.
39.若一个多项式加上-3x2y+2x2-3xy-4得
2x2y+3xy2-x2+2xy,
则这个多项式为______.
40.-5xm-xm-(-7xm)+(-3xm)=______.
41.当a=-1,b=-2时,
[a-(b-c)]-[-b-(-c-a)]=______.
43.当a=-1,b=1,c=-1时,
-[b-2(-5a)]-(-3b+5c)=______.
44.-2(3x+z)-(-6x)+(-5y+3z)=______.
45.-5an-an+1-(-7an+1)+(-3an)=______.
46.3a-(2a-4b-6c)+3(-2c+2b)=______.
48.9a2+[7a2-2a-(-a2+3a)]=______.
50.当2y-x=5时,5(x-2y)2-3(-x+2y)-100=______.
(二)选择
[ ]
A.2;
B.-2;
C.-10;
D.-6.
52.下列各式中计算结果为-7x-5x2+6x3的是 [ ]
A.3x-(5x2+6x3-10x);
B.3x-(5x2+6x3+10x);
C.3x-(5x2-6x3+10x);
D.3x-(5x2-6x3-10x).
53.把(-x-y)+3(x+y)-5(x+y)合并同类项得 [ ]
A.(x-y)-2(x+y);
B.-3(x+y);
C.(-x-y)-2(x+y);
D.3(x+y).
54.2a-[3b-5a-(2a-7b)]等于 [ ]
A.-7a+10b;
B.5a+4b;
C.-a-4b;
D.9a-10b.
55.减去-3m等于5m2-3m-5的代数式是 [ ]
A.5(m2-1);
B.5m2-6m-5;
C.5(m2+1);
D.-(5m2+6m-5).
56.将多项式2ab-9a2-5ab-4a2中的同类项分别结合在一起,应为 [ ]
A.(9a2-4a2)+(-2ab-5ab);
B.(9a2+4a2)-(2ab-5ab);
C.(9a2-4a2)-(2ab+5ab);
D.(9a2-4a2)+(2ab-5ab).
57.当a=2,b=1时,-a2b+3ba2-(-2a2b)等于 [ ]
A.20;
B.24;
C.0;
D.16.
中,正确的选择是 [ ]
A.没有同类项;
B.(2)与(4)是同类项;
C.(2)与(5)是同类项;
D.(2)与(4)不是同类项.
59.若A和B均为五次多项式,则A-B一定是 [ ]
A.十次多项式;
B.零次多项式;
C.次数不高于五次的多项式;
D.次数低于五次的多项式.
60.-{[-(x+y)]}+{-[(x+y)]}等于 [ ]
A.0;
B.-2y;
C.x+y;
D.-2x-2y.
61.若A=3x2-5x+2,B=3x2-5x+6,则A与B的大小是
[ ]
A.A>B;
B.A=B;
C.A<B;
D.无法确定.
62.当m=-1时,-2m2-[-4m2+(-m2)]等于 [ ]
A.-7;
B.3;
C.1;
D.2.
63.当m=2,n=1时,多项式-m-[-(2m-3n)]+[-(-3m)-4n]等于 [ ]
A.1;
B.9;
C.3;
D.5.
[ ]
65.-5an-an-(-7an)+(-3an)等于 [ ]
A.-16an;
B.-16;
C.-2an;
D.-2.
66.(5a-3b)-3(a2-2b)等于 [ ]
A.3a2+5a+3b;
B.2a2+3b;
C.2a3-b2;
D.-3a2+5a-5b.
67.x3-5x2-4x+9等于 [ ]
A.(x3-5x2)-(-4x+9);
B.x3-5x2-(4x+9);
C.-(-x3+5x2)-(4x-9);
D.x3+9-(5x2-4x).
[ ]
69.4x2y-5xy2的结果应为 [ ]
A.-x2y;
B.-1;
C.-x2y2;
D.以上答案都不对.
(三)化简
70.(4x2-8x+5)-(x3+3x2-6x+2).
72.(0.3x3-x2y+xy2-y3)-(-0.5x3-x2y+0.3xy2).
73.-{2a2b-[3abc-(4ab2-a2b)]}.
74.(5a2b+3a2b2-ab2)-(-2ab2+3a2b2+a2b).
75.(x2-2y2-z2)-(-y2+3x2-z2)+(5x2-y2+2z2).
76.(3a6-a4+2a5-4a3-1)-(2-a+a3-a5-a4).
77.(4a-2b-c)-5a-[8b-2c-(a+b)].
78.(2m-3n)-(3m-2n)+(5n+m).
79.(3a2-4ab-5b2)-(2b2-5a2+2ab)-(-6ab).
80.xy-(2xy-3z)+(3xy-4z).
81.(-3x3+2x2-5x+1)-(5-6x-x2+x3).
83.3x-(2x-4y-6x)+3(-2z+2y).
84.(-x2+4+3x4-x3)-(x2+2x-x4-5).
85.若A=5a2-2ab+3b2,B=-2b2+3ab-a2,计算A+B.
86.已知A=3a2-5a-12,B=2a2+3a-4,求2(A-B).
87.2m-{-3n+[-4m-(3m-n)]}.
88.5m2n+(-2m2n)+2mn2-(+m2n).
89.4(x-y+z)-2(x+y-z)-3(-x-y-z).
90.2(x2-2xy+y2-3)+(-x2+y2)-(x2+2xy+y2).
92.2(a2-ab-b2)-3(4a-2b)+2(7a2-4ab+b2).
94.4x-2(x-3)-3[x-3(4-2x)+8].
(四)将下列各式先化简,再求值
97.已知a+b=2,a-b=-1,求3(a+b)2(a-b)2-5(a+b)2×(a-b)2的值.
98.已知A=a2+2b2-3c2,B=-b2-2c2+3a2,C=c2+2a2-3b2,求(A-B)+C.
99.求(3x2y-2xy2)-(xy2-2x2y),其中x=-1,y=2.
101.已知|x+1|+(y-2)2=0,求代数式5(2x-y)-3(x-4y)的值.
106.当P=a2+2ab+b2,Q=a2-2ab-b2时,求P-[Q-2P-(P-Q)].
107.求2x2-{-3x+5+[4x2-(3x2-x-1)]}的值,其中x=-3.
110.当x=-2,y=-1,z=3时,求5xyz-{2x2y-[3xyz-(4xy2-x2y)]}的值.
113.已知A=x3-5x2,B=x2-6x+3,求A-3(-2B).
(五)综合练习
115.去括号:{-[-(a+b)]}-{-[-(a-b)]}.
116.去括号:-[-(-x)-y]-[+(-y)-(+x)].
117.已知A=x3+6x-9,B=-x3-2x2+4x-6,计算2A-3B,并把结果放在前面带“-”号的括号内.
118.计算下式,并把结果放在前面带“-”号的括号内:
(-7y2)+(-4y)-(-y2)-(+5y)+(-8y2)+(+3y).
119.去括号、合并同类项,将结果按x的升幂排列,并把后三项放在带有“-”号的括号内:
120.不改变下式的值,将其中各括号前的符号都变成相反的符号:(x3+3x2)-(3x2y-7xy)+(2y3-3y2).
121.把多项式4x2y-2xy2+4xy+6-x2y2+x3-y2的三次项放在前面带有“-”号的括号内,二次项放在前面带有“+”号的括号内,四次项和常数项放在前面带有“-”号的括号内.
122.把下列多项式的括号去掉,合并同类项,并将其各项放在前面带有“-”号的括号内,再求2x-2[3x-(5x2-2x+1)]-4x2的值,其中x=-1.
123.合并同类项:
7x-1.3z-4.7-3.2x-y+2.1z+5-0.1y.
124.合并同类项:5m2n+5mn2-mn+3m2n-6mn2-8mn.
126.去括号,合并同类项:
(1)(m+1)-(-n+m);
(2)4m-[5m-(2m-1)].
127.化简:2x2-{-3x-[4x2-(3x2-x)+(x-x2)]}.
128.化简:-(7x-y-2z)-{[4x-(x-y-z)-3x+z]-x}.
129.计算:(+3a)+(-5a)+(-7a)+(-31a)-(+4a)-(-8a).
130.化简:a3-(a2-a)+(a2-a+1)-(1-a4+a3).
131.将x2-8x+2x3-13x2-2x-2x3+3先合并同类项,再求值,其中x=-4.
132.在括号内填上适当的项:[( )-9y+( )]+2y2+3y-4=11y2-( )+13.
133.在括号内填上适当的项:
(-x+y+z)(x+y-z)=[y-( )][y+( )].
134.在括号内填上适当的项:
(3x2+xy-7y2)-( )=y2-2xy-x2.
135.在括号内填上适当的项:
(1)x2-xy+y-1=x2-( );
(2)[( )+6x-7]-[4x2+( )-( )]=x2-2x+1.
136.计算4x2-3[x+4(1-x)-x2]-2(4x2-1)的值.
137.化简:
138.用竖式计算
(-x+5+2x4-6x3)-(3x4+2x2-3x3-7).
139.已知A=11x3+8x2-6x+2,B=7x3-x2+x+3,求2(3A-2B).
140.已知A=x3-5x2,B=x3-11x+6,C=4x-3,求
(1)A-B-C;
(2)(A-B-C)-(A-B+C).
141.已知A=3x2-4x3,B=x3-5x2+2,计算
(1)A+B;
(2)B-A.
142.已知x<-4,化简|-x|+|x+4|-|x-4|.
146.求两代数式-1.56a+3.2a3-0.47,2.27a3-0.02a2+4.03a+0.53的差与6-0.15a+3.24a2+5.07a3的和.
-0.3,y=-0.2.
150.已知(x-3)2+|y+1|+z2=0
ZESTRON
2024-09-04 广告
2024-09-04 广告
在Dr. O.K. Wack Chemie GmbH,我们高度重视ZESTRON的表界面分析技术。该技术通过深入研究材料表面与界面的性质,为提升产品质量与可靠性提供了有力支持。ZESTRON的表界面分析不仅涵盖了相变化、化学反应、吸附与解吸...
点击进入详情页
本回答由ZESTRON提供
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询