Question

quais são os valores reais de x que tornam as expressões
$\sqrt{x ^{2} - 9 }$
e
$\sqrt{x + 11}$
iguais?​

Answer 1

$\mathsf{\sqrt{{x}^{2}-9}=\sqrt{x+11}}$

$\mathsf{{x}^{2}-9=11}\\\mathsf{{x}^{2}=11+9}\\\mathsf{{x}^{2}=20}\\\mathsf{x=\sqrt{20}=\sqrt{4.5}=2\sqrt{5}}$