Question

Solve by elimination

Answer 1

$\left\{\begin{array}{ccc}5x-7y=16&\text{multiply both sides by 3}\\-3x+6y=-6&\text{multiply both sides by 5}\end{array}\right\\\underline{+\left\{\begin{array}{ccc}15x-21y=48\\-15x+30y=-30\end{array}\right}\qquad\text{add both sides of equations}\\.\qquad9y=18\qquad\text{divide both sides by 9}\\.\qquad y=2\\\\\\\text{Put the value of y to the first equation}\\\\5x-7(2)=16\\5x-14=16\qquad\text{add 14 to both sides}\\5x=30\qquad\text{divide both sides by 5}\\x=6\\\\Answer:\ x=6\ and\ y=2\to(6,\ 2)$