1) x=0
2)x1=4, x2=-5
1) x + 9x = 0
10х = 0
х = 0
2) x(x + 5) - 4(x + 5) = 0
х² + 5х - 4х - 20 = 0
х² + х - 20 = 0
По теореме Виета:
x1 + x2 = −b ⇒ x₁ = 4
x1 · x2 = c ⇒ x₂ = -5
