Question

A soma das raizes da equação exponencial 5x2+2x=125 é?

Answer 1

$5^{(2+2x)}= 5^3 \\ 2+2x=3 \\ 2x= 3-2 \\ 2x= 1\\ x= 1/2$

Answer 2

$5^{x^2+2x}=125\\\\5^{x^2+2x}=5^3\\\\\therefore\ x^2+2x=3\\\\x^2+2x-3=0\\\\\mathrm{F\acute{o}rmula\ da\ soma\ das\ ra\acute{i}zes\ de\ uma\ equa\text{\c{c}}\tilde{a}o\ do\ segundo\ grau:}\\\\x'+x''=-\dfrac{b}{a}\\\\\\\\x'+x''=-\dfrac{2}{1}\longrightarrow\boxed{{x}'+x''=-2}$