Question

Calcule o valor de 5x² + 15x = 0 para que f (x) =0

Answer 1

Se f(x) = 5x² + 15x , calcular x para f(x) = 0

5x² + 15x = 0 

5x(x + 3) = 0

5x =0 ou (x + 3) = 0

5x = 0 ↔ x = 0

x + 3 = 0 ↔ x = -3

S = {0,-3}

Answer 2

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