(5x-x-40)/(x+40)=3(4x-40)/(x+40)=34x-40=3x+120x=160
5x减x减40的差除以x加40的和等于3怎么解(5x-x-40)÷(x+40)=3(4x-40)÷(x+40)=34x-40=3x+120x=160
