Question

Find the value of x.

$\frac{4}{x}=\frac{2}{5}$

Short answer

The value of x is 10.

Step-by-step solution

Step 1. Given information.

The ratio,

$\frac{4}{x}=\frac{2}{5}$

Step 2. Concept and Formula Used.

The properties of proportion,

if$\frac{a}{b}=\frac{c}{d}$ then,$ad=bc$

The given ratio is, $\frac{4}{x}=\frac{2}{5}$

Step 3. Use the property of proportion, if ab=cd then, ad=bc.

Then,

$20=2x$

Step 4. Divide both sides by 2.

$\begin{array}{l}\frac{2x}{2}=\frac{20}{2}\\ x=10\end{array}$

Therefore, the value of x is 10.