b) \(\frac{x+46}{20}=x\frac{2}{5}\)
\(\Leftrightarrow\frac{x+46}{20}=\frac{5x+2}{5}\)
\(\Leftrightarrow\frac{x+46}{20}=\frac{4\left(5x+2\right)}{20}\)
\(\Rightarrow x+46=4\left(5x+2\right)\)
\(\Leftrightarrow x+46=20x+8\)
\(\Leftrightarrow x-20x=8-46\)
\(\Leftrightarrow-19x=-38\)
\(\Leftrightarrow x=\left(-38\right):\left(-19\right)=2\)
Vậy x=2