\(\dfrac{1}{\sqrt{x^2+8x+16}}=\dfrac{1}{\sqrt{x^2+2.4x+4^2}}=\dfrac{1}{\sqrt{\left(x+4\right)^2}}\)
\(=\dfrac{1}{\left|x+4\right|}=\dfrac{1}{x+4}\)
`ĐK : x + 4 ≠0`
`<=> x ≠-4`
ĐKXĐ: √ ( x + 4 ) 2 <> 0
=>x+4<>0
hay x<>-4
CHO TUI LIKE ĐI :))
ĐKXĐ: \(\sqrt{\left(x+4\right)^2}< >0\)
=>x+4<>0
hay x<>-4