\(\frac{1}{2}-\left(\frac{2}{3}x-\frac{1}{3}\right)=\frac{2}{3}\)
\(\frac{2}{3}x-\frac{1}{3}=\frac{1}{2}-\frac{2}{3}\)
\(\frac{2}{3}x-\frac{1}{3}=\frac{-1}{6}\)
\(\frac{2}{3}x=\frac{-1}{6}+\frac{1}{3}\)
\(\frac{2}{3}x=\frac{1}{6}\)
\(x=\frac{1}{6}:\frac{2}{3}\)
\(x=\frac{1}{4}\)
~ Hok tốt ~
\(\frac{3}{x+5}=15\%\)
\(\Leftrightarrow\frac{3}{x+5}=\frac{15}{100}\)
\(\Leftrightarrow\frac{3}{x+5}=\frac{3}{20}\)
\(\Leftrightarrow x+5=20\)
\(\Leftrightarrow x=20-5\)
\(\Leftrightarrow x=15\)