Answer:
(x, y) = (-4, 15)
Explanation:
The two equations have the same coefficient for y, so you can eliminate y by subtracting one equation from the other. Here the x coefficient is largest for the first equation, so it will work best to subtract the second equation.
(3x +y) -(2x +y) = (3) -(7)
x = -4 . . . . . . . . simplify
Now, we can find y by substituting this value for x.
2(-4) +y = 7
y = 7 +8 = 15 . . . . . add 8 to both sides of the equation
The solution is (x, y) = (-4, 15).