Question

va rog repede dau test​

Answer 1

$\it 5.\ \ \sqrt{3x+4}=4 \Rightarrow (\sqrt{3x+4})^2=4^2 \Rightarrow 3x+4=16|_{-4} \Rightarrow\\ \\ \Rightarrow 3x=12|_{:3} \Rightarrow x=4$

6. Determinăm domeniul de existență a ecuației.

$\left.\begin{aligned}it x+2\geq0 \Rightarrow x\geq-2 \\ \\ x-7\geq0\ \Rightarrow\ x\geq7\end{aligned}\right\} \Rightarrow D=[7,\ \infty)\\ \\ \\ \it Pentru\ x=7\Rightarrow \sqrt{7+2}+\sqrt{7-7}=3\Rightarrow \sqrt9+\sqrt0=3\Rightarrow 3=3\ (A) \\ \\ Deci,\ \ x=7\ este\ solu\c{\it t}ia\ ecua\c{\it t}iei$