方程X+100-20=(X-20)(1+1/3)

问题描述:

方程X+100-20=(X-20)(1+1/3)

X+100-20=(X-20)(1+1/3)
x+80=(x-20)*(4/3)
方程两边同乘以3得
3(x+80)=4(x-20)
3x+240=4x-80
240+80=4x-3x
x=320