2x-4y-14=0 4x+3y+20=-7
{2х-4у=14 ||×(-2) {4х+3у=-27 {-4х+8у=-28 {4х+3у=-27 сложим 4х-4х+3у+8у=-28-27 11у=-55 у=-5 2х-4×(-5)=14 2х+20=14 2х=-6 х=-3 (-3;-5)