Exercício 10: Resolva as equações do 2o grau incompletas, referentes ao 3o caso: a) 6x2 – 24 = 0 f) 2x2 – 32
7x2 = 0
x2 = 0 x = √0 x = 0 S =
x2 = 0
x1 = 0
2x2 – 10x = 0 x . (2x – 10) = 0
^
x2 = 5 S = {0; 2}
2x – 10 = 0
2x = 10
x =
2x2 – 72 = 0 2x2 = 72
x2 = 36 x = ±√36 x = ± 6 S = {-6;
x2 = 72
x2 + 4x = 0 x . (x + 4) = 0
^ x1 = 0 x + 4 = 0
x2 = - 4 S = {0; - 4}
= 0
b) x2 – 49 = 0
g) 8x2 – 128 = 0
c) 5x2 – 20 = 0
h) – x2 + 25 = 0
d) x2 – 7 = 0
i) 4x2 – 400 = 0
e) x2 – 9 = 0
j) 3x2 – 243 = 0