Question

1)Arrume e calcule :

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

Answer 1

Olá,

Resolução:

$x^2+14x+49=9 \\ \\ (x+7)^2=9 \\ \\ x + 7 = \pm \sqrt{9} \\ \\ x -7= \pm 3 \\ \\ x = -7\pm3 \\ \\ \\ x' = -7+3 \rightarrow x'=-4 \\ x" = -7-3\rightarrow x" = -10 \\ \\ S=\left \{ \right -10,-4\}$

Bons Estudos!!

Answer 2

$x^{2}+14x+49=9$
(Igualar a 0)

$x^{2}+14x+49-9=0\\x^{2}+14x+40=0$
resolver por Bhaskara

$\frac{-b_{+/-}\sqrt{b^{2}-4.a.c}}{2.a}\implies\frac{-14_{+/-}\sqrt{14^{2}-4.1.40}}{2}\implies\frac{-14_{+/-}\sqrt{36}}{2}\\\implies\frac{-14_{+/-}6}{2}\\X^{'}=\frac{-14+6}{2}=\frac{-8}{2}=-4\\X^{''}=\frac{-14-6}{2}=\frac{-20}{2}=-10\\S=\{-4, -10\}$