Question

\(\dfrac{x}{5}\) = \(\dfrac{20}{x}\)

Answer 1

\(\dfrac{x}{5}=\dfrac{20}{x}\left(x\ne0\right)\) 

\(\Rightarrow x^2=20.5=100\)

\(\Rightarrow x=10\) hay \(x=-10\)

Answer 2

\(\dfrac{4}{5}\)=\(\dfrac{20}{25}\)

Answer 3

\(\dfrac{4}{5}=\dfrac{20}{25}\)

Answer 4

\(\dfrac{20}{25}\)

Answer 5

4/5=20/25

Answer 6

4/5 = 20/25

Answer 7

\(\dfrac{x}{5}=\dfrac{20}{x}\)

\(\Leftrightarrow x\times x=20\times5\)

\(\Leftrightarrow x\times x=100=10\times10\)

\(\Rightarrow x=10\)

Answer 8

\(=> x.x=5.20\)

\(=> x^2 =100\)

\(=> \begin{cases} x^2=10^2\\ x^2=(-10)^2 \end{cases}\)

\(=>x={10;-10}\)