4x-y=-38
x+y=3
Add the system together.
4x+x= 5x
-y+y= 0 (the y's cancel out, that's why we can do this)
-38+3= -35
5x=-35
Divide both sides by 5.
x=-7
Now, plug that in.
-7+y=3
Add -7 on both sides,
y=10
The solution is: (-7, 10)
I hope this helps!
~kaikers