1) x^2 - 14x - 32 = 0
(x - 16)(x + 2) = 0
x1 = 16
x2 = -2

2) 5x^2 - 12x + 7 = 0
No real roots

3) -2x^2 + x + 15 = 0
(-2x - 3)(x - 5) = 0
x1 = -3/2
x2 = 5

4) -2y^2 + 9y - 10 = 0
(-2y + 5)(y - 2) = 0
y1 = 5/2
y2 = 2

Уравнение 20Б не указано в вопросе.