Question

(3x2 + 1) – 3(x + 2)2 = -9

Answer 1

Resposta:

$(3 {x}^{2} + 1) - 3( {x + 2)}^{2} = - 9$

$3x {}^{2} - 3(x + 2)(x + 2) = - 9$

${3x}^{2} + 1 - 3( {x}^{2} + 2x + 2x + 4) = - 9$

$3 {x}^{2} + 1 - 3( {x}^{2} + 4x + 4) = - 9$

$3 {x}^{2} + 1 - 3 {x}^{2} - 12x - 12 = - 9$

$- 12x - 11 = - 9$

$- 12x = - 9 + 11$

$- 12x = 2$

$x = \frac{2}{ - 12}$

$x = - \frac{1}{6}$