Question

$\left \{ {{4x=-6y} \atop {7y-2x=20}} \right.$

Answer 1

4x=-6y⇒x=-6y/4=-3y/2
7y-2x=20⇒7y-2(-3y/2)=20⇒7y+3y=20⇒10y=20⇒y=20/10⇒y=2
x=-3y/2=-6/2=-3