solution is (- 1, 1 )
given the 2 equations
2x - y = - 3 → (1)
x + y = 0 → (2)
add (1) and (2) term by term to eliminate the term in y
3x = - 3 ( divide both sides by 3 )
x = - 1
substitute x = - 1 in either of the 2 equations and solve for y
(2) : - 1 + y = 0 ( add 1 to both sides )
y = 1
solution is (- 1, 1 )