3*(0,2х+0,4y)+(1,6х+2,8y)*2 = 0,6x + 1,2y + 2(1,6x + 2,8y) = 0,6x + 1,2y + 3,2x + 5,6y = 3,8x + 6,8y
0.8y + 1.4 = 0.4y – 2.6
0,8y – 0,4y = – 2,6 – 1,4
0.4y = -4
y = -10
3*(0,2х+0,4y)+(1,6х+2,8y)*2 = 0,6x + 1,2y + 2(1,6x + 2,8y) = 0,6x + 1,2y + 3,2x + 5,6y = 3,8x + 6,8y
0.8y + 1.4 = 0.4y – 2.6
0,8y – 0,4y = – 2,6 – 1,4
0.4y = -4
y = -10