小学方程题1 x-3=5x-72 15*(x-8)-4*(2x+3)=6*(x-4)-1003 8x=6x+8 4 11

1 x-3=5x-7
x=5x-7+3
x=5x-4
x+4=5x
5x-x=4
x=1
2 15*(x-8)-4*(2x+3)=6*(x-4)-100
15x-120-8x-12=6x-24-100
7x-132=6x-124
7x-6x=132-124
x=8
3 8x=6x+8
8x-6x=8
x=4
4 11x+46-4x=100-9x-22
7x+46=78-9x
7x+9x=78-46
x=2
5 8x-5+2x+1=7x+6-5x
10x-4=2x+6
10x-2x=6+4
x=1.25
6 408x-2=3.2x+3.4
408x-3.2x=3.4+2
404.8x= 5.4
x=0.013
7 6x-7=5x+2x
6x-7=7x
6x=7x+7
6x-7x=7
-x=7
x=-7
(用小学法）

1X=1

8.6x-5.4x=6.4]
[8.6-5.4]x=6.4
3.2x =6.4
3.2x/3.2=6.4/3.2
=2