2.) 2x^2 - 3x - 14 = 0
2x^2 + 4x - 7x - 14 = 0
2x(x + 2) - 7(x + 2) = 0
(2x - 7)(x + 2) = 0
3.) x^2 + 7x = 18
x^2 + 7x - 18 = 0
x^2 - 2x + 9x - 18 = 0
x(x - 2) + 9(x - 2) = 0
(x + 9)(x - 2) = 0
4.) 9x^2 + 30x + 25 = 9x^2 + 15x + 15x + 25 = 3x(3x + 5) + 5(3x + 5) = (3x + 5)(3x + 5) = (3x + 5)^2
5.) x^2 - 14x + 49 = x^2 - 7x - 7x + 49 = x(x - 7) - 7(x - 7) = (x - 7)(x - 7) = (x - 7)^2