Question

помогите плиз!!!!!
$left { {{4(x+y) ^{2}-7(x+y)=15 } atop {5x-2y=1}} right.$

Answer 1

 
 $5x-2y=1\ 5x+5y-7y=1\ 5(x+y)=1+7y\ x+y=frac{1+7y}{5}\\ 4*frac{1+14y+49y^2}{25}-7*frac{1+7y}{5}=15\ 28y^2-27y-58=0\ D=7225\ y=-frac{29}{28}\ y=2\ x=1\ x=-frac{3}{14}$