Answer: 5x^2 + 20x + 20 = 0 and
x^2 + 6x + 9 = 0
Explanation:
x^2 - x - 6 = 0
(x + 2) (x - 3) = 0
x = -2, 3 (two solutions)
5x^2 + 20x + 20 = 0
5(x^2 + 4x + 4) = 0
5 (x + 2)^2
x = -2 (one solution)
9x^2 - 25 = 0
(3x - 5) (3x + 5) = 0
x = +/- 5/3 (two solutions)
4x^2 + 4x = 0
4x (x + 1) = 0
x = 0, -1 (two solutions)
x^2 + 6x + 9 = 0
(x + 3)^2 = 0
x = -3 (one solution)