Question

4 = 1

x = 5

Answer 1

\(\frac{4}{x}=\frac{1}{5}\)

\(\frac{1}{5}=\frac{1\cdot4}{5\cdot4}\) ( vì 4 : 1 = 4 ) \(=\frac{4}{20}\)

\(\Rightarrow x=20\)

Answer 2

\(\)VÌ \(\frac{1\cdot4}{5\cdot4}\)\(=\)\(\frac{4}{20}\)\(\Rightarrow\)\(\frac{1=4}{5=20}\)