2.5x - 3y = -13 (1)
3.25x - y = -14 ⇒ y = 3.25x + 14 (2)
Sub (2) into (1) and we have
2.5x - 3 [ 3.25x + 14] = -13 simplify
2.5x - 9.75x - 42 = -13
-7.25x - 42 = -13 add 2 to both sides
-7.25x = 29 divide both sides by -7.25
x = -4
And using (2), y = 3.25(-4) + 14 = -13 + 14 = 1
So {x, y} = { -4, 1 }