解方程:(6x+12)/(x+5)=28

问题描述:

解方程:(6x+12)/(x+5)=28

(6x+12)/(x+5)=28
(3x+6)/(x+5)=14
3x+6=14(x+5)
3x+6=14x+70
11x=-64
x=64/11

(6x+12)/(x+5)=28
6x+12=28x+28*5
22x=128
x=64/11

两边同乘以(x+5)得:6x+12=28(x+5)
6x+12=28x+140
12-140=28x-6x
-128=22x
x=-64/11