Question

7x — 9y = 12—7x – 7y = -28

Answer 1

In order to solve this system of equations, we can add both equations, this way we can find the value of y and then the value of x:

`\begin{gathered} \begin{cases}7x-9y=12 \\ -7x-7y=-28\end{cases} \\ 7x-9y-7x-7y=12-28 \\ -16y=-16 \\ y=(-16)/(-16)=1 \\ \\ 7x-9=12 \\ 7x=21 \\ x=(21)/(7) \\ x=3 \end{gathered}`

So the solution to this system is (3, 1).