6x+19x=22.5
(6+19)x=22.5
15x=22.5
x=1.5
x+17%=9.36
x+0.17=9.36
x=9.36-0.17
x=9.19
78%x=39
x=39÷78%
x=39÷0.78
x=50
70%x-18%x=3.12
(70%-18%)x=3.12
52%x=3.12
x=3.12÷52%
x=6
12x+53=137
12x=137-53
12x=84
x=84÷12
x=7