7.8х - 4.6х + 0.8=12 И второе 3.32х+0.97х+0.74=2
1) 3.2х+0.8=12 3.2х=12-0.8 3.2х=11.2 х=3.5
3.32х+0.97х+0.74=2 4.29х=1.26 х=1.26/4.29