Question

数学简便运算

简便算法：5.7x-2.8x-2.9=0
4.6x+2.7x3=54.1
(x-3.5)/4.5=2
x/6.9-2.6=5.6
23.12x0.15=
1.3635/1.35=
9.7161/2.33
3.5x2.6+10.5x18+35x2=
4.6x10.1=
8.9x2.5/4=

Answer 1

1)5.7x-2.8x-2.9=0
2.9x=2.9
x=1
2)4.6x+2.7x3=54.1
4.6x=54.1-6-2.1=46
x=10
3) (x-3.5)/4.5=2
x-3.5=9
x=12.5
4)x/6.9-2.6=5.6
x=6.9*8.2=(7-0.1)*8.2=57.4-0.82=56.58
5)23.12x0.15=(23.12x0.3)/2=6.936/2=3.468
6)1.3635/1.35=(1.35+0.0135）/1.35=1+0.01=1.01
7) 9.7161/2.33=（9.32+0.233+0.1631）/2.33=4+0.1+0.07=4.17
8)3.5x2.6+10.5x18+35x2=3.5x2+3.5x0.6+180+9+70=7+2.1+259=268.1
9)4.6x10.1=46+0.46=46.46
10)8.9x2.5/4=8.9x2.5x4/16=89/16

Answer 2

1、5.7x-2.8x-2.9=0
2.9x=2.9
x=1
2、 4.6x+2.7x3=54.1
4.6x=54.1-8.1=46
x=10
3、 (x-3.5)/4.5=2
x-3.5=9
x=12.5
4、 x/6.9-2.6=5.6
x/6.9= 8.2
x=8.2*6.9=8.2*（7-0.1）=57.4-0.82=53.58
5、 23.12x0.15= 23.12*0.5*0.3=11.56*0.3=34.68
6、 1.3635/1.35=（1.35+0.0135）/1.35=1+0.01=1.01
7、9.7161/2.33=（9.32+0.233+0.1631）/2.33=4+0.1+0.07=4.17
8、3.5x2.6+10.5x18+35x2=3.5（26+54+20）=3.5*100=350
9、 4.6x10.1=4.6*（10+0.1）=46+0.46=46.46
10、 8.9x2.5/4=（8+0.8+0.1）*2.5/4=（20+2+0.25）/4=111/16
谢谢

Answer 3

5.7x-2.8x-2.9=0
4.6x+2.7x3=54.1
(x-3.5)/4.5=2
x/6.9-2.6=5.6
23.12x0.15=
1.3635/1.35=
9.7161/2.33
3.5x2.6+10.5x18+35x2=
4.6x10.1=
8.9x2.5/4=

Answer 4

要精确答案吗？
23.12x0.15= 23.12x0.3/2=
1.3635/1.35=1.1（这个直接除）
9.7161/2.33=（9.32+0.233+0.1631）/2.33=4+0.1+0.07=4.17
3.5x2.6+10.5x18+35x2=3.5（26+54+20）=3.5*100=350
4.6x10.1=4.6x10+4.6x0.1=46.46
8.9x2.5/4=4x8.9x2.5/（4x4）=111/16

Answer 5