Question

Resolva a equação:

(3x -1)² - 3(2x + 3)² + 42 = 2x(-x -5) - (x - 1)²

Answer 1

$9 {x}^{2} - 6x + 1 - 3(4 {x}^{2} + 12x + 9) + 42 = - 2 {x}^{2} - 10x - ( {x}^{2} - 2x + 1)$

$9 {x}^{2} - 6x + 1 - 12 {x}^{2} - 36x - 27 + 42 = - 2 {x}^{2} - 10x - {x}^{2} + 2x - 1$

$- 3 {x}^{2} - 42x + 16 = - 3 {x}^{2} - 8x - 1$

$- 3 {x}^{2} + 3 {x}^{2} - 42x + 8x = - 1 - 16$

$- 34x = - 17$

$- x = - \frac{1}{2}$

$x = \frac{1}{2}$