Question

Resolva as equações
A) -2x² + 6x -2 =2
B) -x² -3x +4=0​

Answer 1

Explicação passo-a-passo:

A)

${ - 2x}^{2} + 6x - 2 = 2$

${ - 2x}^{2} + 6x - 2 - 2 = 0$

${ - 2x}^{2} + 6x - 4 = 0$

${x}^{2} - 3x + 2 = 0$

$x = \frac{ - ( - 3)± \sqrt{ {( - 3)}^{2} - 4 \times 1 \times 2} }{2 \times 1}$

$x = \frac{ - ( - 3)± \sqrt{ {( - 3)}^{2} - 4 \times 2 } }{2 \times 1}$

$x = \frac{ - ( - 3)± \sqrt{ {( - 3)}^{2} - 4 \times 2} }{2}$

$x = \frac{3± \sqrt{ {( - 3)}^{2} - 4 \times 2} }{2}$

$x = \frac{3± \sqrt{9 - 4 \times 2} }{2}$

$x = \frac{3± \sqrt{9 - 8} }{2}$

$x = \frac{3± \sqrt{1} }{2}$

$x = \frac{3±1}{2}$

$x = \frac{3 + 1}{2} \\ x = \frac{3 - 1}{2}$

$x = 2 \\ x = 1$

$x_{1} = 1 \\ x_{2} = 2$

B)

${ - x}^{2} - 3x + 4 = 0$

${x}^{2} + 3x - 4 = 0$

$x = \frac{ - 3± \sqrt{ {3}^{2} - 4 \times 1 \times ( - 4) } }{2 \times 1}$

$x = \frac{ - 3± \sqrt{ {3}^{2} - 4 \times ( - 4)} }{ 2\times 1}$

$x = \frac{ - 3± \sqrt{ {3}^{2} - 4 \times ( - 4)} }{2}$

$x = \frac{ - 3± \sqrt{9 - 4 \times ( - 4)} }{2}$

$x = \frac{ - 3± \sqrt{9 + 16} }{2}$

$x = \frac{ - 3± \sqrt{25} }{2}$

$x = \frac{ - 3±5}{2}$

$x = \frac{ - 3 + 5}{2} \\ x = \frac{ - 3 - 5}{2}$

$x = 1 \\ x = - 4$

$x_{1} = - 4 \\ x_{2} = 1$

ATT:ARMANDO