Replace y with x + 3. x^2 + 2(x+3) = 9 2) Expand the bracket, and subtract 9. x^2 + 2x - 3 = 0 3) Factorise the quadratic(x - 1)(x + 3) = 0 4) Therefore, x has 2 solutions. x = 1 and x = -3. 5) Find corresponding y solutions by substituting these values of x into the second equation. ==> x = 1, y = 4 and x = -3, y = 0