For 𝑎 = 3, 𝑏 = -4, 𝑥 = -9, 𝑦 = 8 the point (𝑎 + 𝑏, 𝑥 - 𝑦) lies in which quadrant?
For x = 3, y = 2, u = -9, v = 13 the point (x+y, u+v) lies in which quadrant?