6x-2(340-3x)=220 18+0.4x=22.2-x
1个回答

6x-2(340-3x)=220

6x-680+6x=220

6x+6x=680+220

12x=900

x=75

18+0.4x=22.2-x

0.4x+x=22.2-18

1.4x=4.2

x=3