2/3х + 1/2х - 1 = 2 - 1/3х + 2 1/4
2/3х + 1/2х + 1/3х = 1 + 2 + 2 1/4
4/6х + 3/6х + 2/6х = 5 1/4
9/6х = 5 1/4
х = 5 1/4 : 9/6
х = 21/4 : 9/6
х = 7/2
х = 3,5
3х=(х+12)*2,5
3х=2,5х+30
3х-2,5х=30
0,5х=30
х=60
(y-1.8):0.7=1.3
у-1.8=1.3*0.7
у-1.8=0.91
у=0.91+1.8
у=2.71