Question

Answer 1

\(h.10-\sqrt{x}-5=25\left(ĐK:x\ge0\right)\)

\(\Leftrightarrow-\sqrt{x}=20\)

\(\Leftrightarrow\sqrt{x}=-20\left(vô.lí\right)\)

Vậy nghiệm của PT là \(S=\varnothing\)

 

Answer 2

\(i.\dfrac{x}{3}=\dfrac{12}{x}\)

\(\Leftrightarrow x^2=36\)

\(\Leftrightarrow\left|x\right|=6\)

\(\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-6\end{matrix}\right.\)

Answer 3

\(e.\left(2x+1\right)^2=\dfrac{36}{25}\)

\(\Leftrightarrow\left|2x+1\right|=\dfrac{6}{5}\)

\(\Leftrightarrow\left[{}\begin{matrix}2x+1=\dfrac{6}{5}\\2x+1=-\dfrac{6}{5}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{10}\\x=-\dfrac{11}{10}\end{matrix}\right.\)

Answer 4

h,\(10.\sqrt{x}-5=25 \)
\(10.\sqrt{x}=25+5=30 \)
\(\sqrt{x}=3\)
=>x=9
i,\(\dfrac{x}{3}=\dfrac{12}{x}\)
=>\(x^2=36\)
=>x=6 hoặc (-6)