4x+5=5x-4 x=?

问题描述:

4x+5=5x-4 x=?

9

5x-4x=4+5 x=9

移项
5x-4x=5+4
x=9

4x+5=5x-4
5-(-4)=5x-4x
9=x
x=9

4x+5=5x-4
x=9

5x-4x=5+4
x=9