1.2х-(-0.4х +2.4у) , если 3у -2х = - 5
1.2х-(-0.4х +2.4у) , если 3у -2х = - 5 3y = -5+2x y = -5+2x /3 6/5x + 2/5x - 12/5 * (-5+2x /3) = 8/5x -4*(-5+2x)/5= 8/5x + 20-8x /5 = 20