Question

Find the solution of this system of equations 10x-7y=-1 and -2x-7y=-25

Answer 1

x = 2, y = 3 → (2, 3)

Explanation:

`\left\{\begin{array}{ccc}10x-7y=-1\\-2x-7y=-25&\text{change the signs}\end{array}\right\\\underline{+\left\{\begin{array}{ccc}10x-7y=-1\\2x+7y=25\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad12x=24\qquad\text{divide both sides by 12}\\.\qquad x=2\\\\\text{Put it to the second equation}\\2(2)+7y=25\\4+7y=25\qquad\text{subtract 4 from both sides}\\7y=21\qquad\text{divide both sides by 7}\\y=3`