Question

essa ai como q resolver

Answer 1

Boa tarde !

Solução!

$x^{2} +18x+81=0\\\\ a=1\\\\ b=18\\\\ c=81$

Formula de Bhaskara!

$x= \dfrac{-b\pm \sqrt{b^{2}-4.a.c} }{2.a}\\\\\\\\ x= \dfrac{-18\pm \sqrt{18^{2}-4.1.81} }{2.1}\\\\\\\\ x= \dfrac{-18\pm \sqrt{324-324} }{2.1}\\\\\\\\ x= \dfrac{-18\pm \sqrt{0} }{2}\\\\\\\\ x= \dfrac{-18\pm 0}{2}\\\\\\\\ Duas~~raizes~~iguais!\\\\\\\ x_{1}= x_{2}= \dfrac{-18}{2}\\\\\\\ x_{1}= x_{2}= -9\\\\\\\ Resposta:\\\\\\ S=\{-9\}$

Boa tarde!

Bons estudos!