Question

resolve as equaçoes do 2 grau incompletas sem a formula
a) 9x²+15x=0
b) 6x²-216=0

Answer 1

a) 9x² + 15x = 0

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


3x + 5 = 0  ------ 3x = -5 ------ x = - 5/3

S = {- 5/3, 0}


b) 6x² - 216 = 0

6x² = 216 ----- 6x² = 216 ------  x² = 216/6  ------- x² = 36

x = +-√36 -------  x = +- 6


S = {- 6, 6}