Question

a) x*(x+2)=3 me ajuda com essas perguntas
b) x*(x-2)=2*(x+6) ​

Answer 1

Explicação passo-a-passo:

a) x × (x + 2) = 3

x² + 2x = 3

x² + 2x - 3 = 0

$x = \frac{ - 2 + - \sqrt{ {2}^{2} - 4 \times 1 \times ( - 3)} }{2 \times 1} \\ \\ x = \frac{ - 2 + - \sqrt{4 + 12} }{2} \\ \\ x = \frac{ - 2 + - \sqrt{16} }{2} \\ \\ x1 = \frac{ - 2 + 4}{2} = \frac{2}{2} = 1 \\ \\ x2 = \frac{ - 2 - 4}{2} = \frac{ - 6}{2} = - 3$

b) x × (x - 2) = 2 × (x + 6)

x² - 2x = 2x + 12

x² - 2x - 2x - 12 = 0

x² - 4x - 12 = 0

$x = \frac{ - ( - 4) + - \sqrt{ {( - 4)}^{2} - 4 \times 1 \times ( - 12)} }{2 \times 1} \\ \\ x = \frac{4 + - \sqrt{16 + 48} }{2} \\ \\ x = \frac{4 + - \sqrt{64} }{2} \\ \\ x1 = \frac{4 + 8}{2} = \frac{12}{2} = 6 \\ \\ x2 = \frac{4 - 8}{2} = \frac{ - 4}{2} = - 2$