Question

x. (x+7)=30 Equação do 2 grau​

Answer 1

x . (x+7) = 30

x² + 7x = 30

x² + 7x - 30 = 0

∆ = 7² - 4.1.(-30)

∆ = 49 + 120

∆ = 169

$x = \frac{ - 7 + - \sqrt{169} }{2 \times 1}$

$x = \frac{ - 7 + - 13}{2}$

$x1 = \frac{ - 7 + 13}{2} \\ x2 = \frac{ - 7 - 13}{2}$

$x1 = 3 \\ x2 = - 10$

Answer 2

Resposta:

${x}^{2} + 7x = 30 \\ {x}^{2} + 7x - 30 = 0 \\ 49 + 120 = 169 \\ \frac{ - 7 + - 13}{2} \\ x1 = 3 \\ x2 = - 10$