Answer:
solution is (7, - 3 )
Explanation:
given the system of equations
x - y = 10 → (1)
3x + y = 18 → (2)
adding the 2 equations term by term will eliminate y
(x + 3x) + (- y + y) = 10 + 18
4x + 0 = 28
4x = 28 ( divide both sides by 4 )
x = 7
substitute x = 7 into either of the 2 equations and solve for y
substituting into (2)
3(7) + y = 18
21 + y = 18 ( subtract 21 from both sides )
y = - 3
the solution is (7, - 3 )