Question

Resolva a equação do segundo grau imcompleta:
1) x² + x (x – 6) = 0
2) 3(x² - 1) = 24
3) 8x² = 0

Answer 1

Oie, Td Bom?!

1.

$x {}^{2} + x \: . \: (x - 6) = 0$

$x \: . \: (x + x - 6) = 0$

$x \: . \: (2x - 6) = 0$

$x \: . \: 2(x - 3) = 0$

$x \: . \: (x - 3) = 0$

• $x = 0$

• $x - 3 = 0⇒x = 3$

$S = \left \{ 0 \: ,\: 3\right \}$

2.

$3 \: . \: (x {}^{2} - 1) = 24$

$x {}^{2} - 1 = \frac{24}{3}$

$x { }^{2} - 1 = 8$

$x {}^{2} = 8 + 1$

$x {}^{2} = 9$

$x = ± \sqrt{9}$

$x = ±3$

$S = \left \{ - 3 \: , \: 3\right \}$

3.

$8x {}^{2} = 0$

$x {}^{2} = \frac{0}{8}$

$x {}^{2} = 0$

$x = 0$

$S = \left \{ 0\right \}$

Att. Makaveli1996