Question

7²+7x+7x+x²
É igual a quanto?​

Answer 1

Resposta:

7²+7x+7x+x² =

49 + 7x + 7x + x² =

x² + 14x + 49 = 0

a = 1       b = 14       c = 49

$x = \frac{-(b) +- \sqrt{(b)^{2} - 4 * a * c} }{2*a}\\\\x = \frac{-(14) +- \sqrt{(14)^{2} - 4 * 1 * 49} }{2*1}\\\\x = \frac{-14+-\sqrt{196-196} }{2}\\\\x = \frac{-14+-\sqrt{0} }{2}\\\\x = \frac{-14+-0}{2} \\\\x = \frac{-14}{2}=-7$