Решите неравенства:
a) x2 - 9 > 0;
в) -2x2 + 5x - 2 < 0.

1) x² - 9 > 0

x² > 9

x > √9

x > 3 или x < -3

(-∞;-3)∪(3;+∞)

2) -2x² + 5x - 2 < 0

D = 25 - 4*(-2)*(-2) = 25 - 16 = 9

x₁ = (-5 + √9)/2*(-2) = -2/-4 = 1/2

x₂ = (-5 - √9)/2*(-2) = -8/-4 = 2

(-∞;1/2)∪(2;+∞)