2x+30%x=13.8 13:x=6.5:4
:x=: 2:=3.6:x 12-4x=2.4
76x=136.8 9.2+0.8x=11.6 7x+3x-25=73
6x-18=120 x÷9=12.6 *3.8x-x=0.56