First, we merge the questions, to do that we simplify both of them to get a positive side.
To do that, we can first mutliply both sides of the second equation by -1.
Due to that, we get the equations
-9x+5y=5
5x-5y=15
If we add up the equations, we get -4x = 20
We can simplify and get x=-5
To get y, we can first input x into the second equation:
5(-5)-5y=15
-25-5y=15
Simplify and we get -8.
Therefore we have (-5,-8)
