Here is the answer I believe. It goes in a x all it did was added to to each x and y (-3,0)
and 
use the second expression to calculate the left-hand side of the first equation:

Add 10 to both sides if this equation to get

and divide both sides by 2

this proves that x = 17, give the two initial equations
Tenth have to make answer longer for this app sorry
Answer:
7
Step-by-step explanation: