1.7x-(0.2x+2y) если 4y-3x=6
1,7x-(0,2x+2y)=1,7x-0,2x-2y=1,5x-2y 4y-3x=6 <=>3x-4y=-6 <=> 2(1,5x-2y)=-6 <=>1,5x-2y=-3