x/12+20/60=(x-4)/9怎么解快.

x/12+20/60=(x-4)/9怎么解快.
x/12+20/60=(x-4)/9怎么解
快.

x/12+20/60=(x-4)/9怎么解快.
x/12+20/60=(x-4)/9
化简得
x/12+1/3=(x-4)/9
等号两边同时乘以36,去分母得
3x+12=4(x-4)
3x+12=4x-16
4x-3x=12+16
x=28

3x+12=4(x-4)
3x+12=4x-16
x=28