4x+20=2(x+30) 5(x-1)-2(0.5x-1)=7 怎么解?
问题描述:
4x+20=2(x+30) 5(x-1)-2(0.5x-1)=7 怎么解?
答
4x+20=2(x+30)
4x+20=2x+60
4x-2x=60-20
2x=40
x=20
5(x-1)-2(0.5x-1)=7
5x-5-x+2=7
5x-x=7+5-2
4x=10
x=2.5