Question

Determine a raiz do polinomio: P(x)= 3.(x-5).(x+6)

Answer 1

3 ( x - 5) ( x + 6) =
(3x - 15 ) ( x +6) =
3x² + 18x - 15x - 90 = 0
3x²  + 3x - 90 = 0
delta = 9 + 1080 = 1089 ou +-V1089  = +-33 ***

x = ( -3 +-33)/6
x1 =  30/6 = 5 ***
x2 = -36/6 = - 6 ***