3y-1/2=1/3 x-8=2x+7 2x=5x-1 9-10x=9x-10 4/5x=5x-21

解方程得窍门:把未知数一边的通过4则运算化简最后剩下未知数,即可求得方程.
(1)3y-1/2=1/3
3y=1/3 +1/2
3y=5/6
y=5/18
(2)x-8=2x+7
x=2x+7+8
x=2x+15
0=x+15
x=-15
(3)2x=5x-1
0=3x-1
3x=1
x=1/3
(4)9-10x=9x-10
9=19x-10
19=19x
x=1
(5)4/5x=5x-21
4x=25x-105
105=21x
x=5