Question

D) x² + 14x + 49 = 9

Answer 1

D) $x^{2} + 14x + 49 = 9$

$x^{2} + 14x + 49 - 9 = 0$

$x^{2} + 14x + 40 = 0$

Δ  = $14^{2} - 4 .1.40$

Δ  = 196 - 160

Δ  = 36

$x = \frac{-14±\sqrt{36} }{2.1}$

$x=\frac{-14+-6}{2}$

$x^{1} = \frac{-14-6}{2} = -10$

$x^{2} = \frac{-14+6}{2} =-4$