Question

 help mee! pls

Answer 1

ĐKXĐ: \(\left[{}\begin{matrix}x< =\dfrac{-5-\sqrt{17}}{2}\\x>=\dfrac{-5+\sqrt{17}}{2}\end{matrix}\right.\)

\(\left(x+1\right)\left(x+4\right)-3\sqrt{x^2+5x+2}=6\)

=>\(\left(x^2+5x+4\right)-3\sqrt{x^2+5x+2}-6=0\)

=>\(\left(x^2+5x+2\right)-3\sqrt{x^2+5x+2}-4=0\)

=>\(\left(\sqrt{x^2+5x+2}-4\right)\left(\sqrt{x^2+5x+2}+1\right)=0\)

=>\(\sqrt{x^2+5x+2}-4=0\)

=>\(\sqrt{x^2+5x+2}=4\)

=>\(x^2+5x+2=16\)

=>\(x^2+5x-14=0\)

=>(x+7)(x-2)=0

=>\(\left[{}\begin{matrix}x=-7\left(nhận\right)\\x=2\left(nhận\right)\end{matrix}\right.\)