a: \(\sqrt{\left(x+1\right)^2}=5\)(ĐKXĐ: \(x\in R\))
=>|x+1|=5
=>\(\left[{}\begin{matrix}x+1=5\\x+1=-5\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\left(nhận\right)\\x=-6\left(nhận\right)\end{matrix}\right.\)
b: Sửa đề: \(5\sqrt{9x-9}-\sqrt{4\left(x-1\right)}+\sqrt{36\left(x-1\right)}-18=0\)
ĐKXĐ: x>=1
\(PT\Leftrightarrow5\cdot3\sqrt{x-1}-2\sqrt{x-1}+6\sqrt{x-1}-18=0\)
=>\(15\sqrt{x-1}-2\sqrt{x-1}+6\sqrt{x-1}=18\)
=>\(19\sqrt{x-1}=18\)
=>\(\sqrt{x-1}=\dfrac{18}{19}\)
=>\(x-1=\left(\dfrac{18}{19}\right)^2=\dfrac{324}{361}\)
=>\(x=\dfrac{324}{361}+1=\dfrac{324+361}{361}=\dfrac{685}{361}\)
Lời giải:
a. PT $\Leftrightarrow |x+1|=5$
$\Leftrightarrow x+1=\pm 5\Leftrightarrow x=4$ hoặc $x=-6$
b. ** Sửa $x-9$ thành $x-1$
ĐKXĐ: $x\geq 1$
PT $\Leftrightarrow 5\sqrt{x-1}-2\sqrt{x-1}+6\sqrt{x-1}-18=0$
$\Leftrightarrow (5-2+6)\sqrt{x-1}=18$
$\Leftrightarrow 9\sqrt{x-1}=18$
$\Leftrightarrow \sqrt{x-1}=2$
$\Leftrightarrow x-1=4$
$\Leftrightarrow x=5$ (tm)