Question

x+1分之3-y+2分之4=0 x-3分之4-y-3分之3=12分之1 求解 要过程

是二元一次方程组

Answer 1

3/(x+1)-4/(y+2)=0
4/(x-3)-3/(y-3)=1/12

3/(x+1)-4/(y+2)=0
3(y+2)=4(x+1)
y=4(x+1)/3-2=4/3x-2/3

4/(x-3)-3/(y-3)=1/12

48(y-3)-36(x-3)=(y-3)(x-3)
(48-x+3)(y-3)-36(x-3)=0
把y=4/3x-2/3代入得：
(51-x)(4/3x-2/3)-36(x-3)=0
(51-x)(2x-1)-54(x-3)=0
102x-51-2x²+x-54x+162=0
2x²-49x-111=0
x={49±√[(-49)²-4*2*(-111)]}/2*2=(49±√3289)/4

y=4/3x-2/3=y=4/[3*(49±√3289)/4]-2/3=16/3*(49±√3289)-2/3

Answer 2

3/(x+1)-4/(y+2)=0
4/(x-3)-3/(y-3)=1/12

3/(x+1)=4/(y+2)
4(x+1)=3(y+2)
4X+4=3y+6
4X=3y+2
x=(3y+2)/4

4/(x-3)-3/(y-3)=1/12
4=[3/(y-3)+1/12]*{[(3y+2)/4]-3}
4=[3/(y-3)+1/12]*(3y-10)/4
16=[3/(y-3)+1/12]*(3y-10)
计算求解.....后面实在不想算了...

追问

我要一个准确的值...........

追答

3/(x+1)-4/(y+2)=0
4/(x-3)-3/(y-3)=1/12

3/(x+1)=4/(y+2)
4(x+1)=3(y+2)
4X+4=3y+6
4X=3y+2
x=(3y+2)/4

4/(X-3)-3/(Y-3)=1/12
4/(X-3)=3/(Y-3)+1/12
48/(X-3)=36/(Y-3)+1
48/(X-3)=[36+(Y-3)]/(Y-3)
48/(X-3)=(33+Y)/(Y-3)
48(y-3)=(x-3)(33+y)
将x=(3y+2)/4带入
[(3y+2)/4-3](33+y)=48(y-3)
[4-3(3y-+2)]/(3y+2)=(48y-144)/(33+y)
(-2-9y)/(3y+2)=(48y-144)/(33+y)
-(9y+2)(33+y)=(3y+2)(48y-144)
-(297y+9yy+66+2y)=144yy-432y+96y-288
-297y-9yy-66-2y=144yy-432y+96y-288
-299y-9yy-66=144yy-336y-288
336y-299y-66+288-144yy-9yy=0
37y+222-153yy=0
153yy-37y-222=0
貌似计算有问题，你自己带入计算下好不