Question

Calcule as raízes reais das equações A) x2 + 12x + 27= 0B) x2 - 10x + 21= 0C) x2 + 11x + 30= 0D) x2- 3x - 4= 0Escreva na fatorado as equações A) x2 -5x -6= 0B) x2+ 13x + 42= 0

Answer 1

Boa noite 

a)

x² + 12x + 27 = (x + 3)*(x + 9) = 0

x1 = -3
x2 = -9

b)

x² - 10x + 21 = (x - 3)*(x - 7) = 0

x1 = 3
x2 = 7

c)

x² + 11x + 30 = (x + 5)*(x + 6) = 0

x1 = -5
x2 = -6

a)

x² - 5x - 6 = (x - 2)*(x - 3) = 0

b)


x² + 13x + 42 = (x + 6)*(x + 7)