Q10. - Algebra 1

Question

Record your answers on the answer sheet provided by your teacher or on a sheet of paper.

Solve the proportion $\frac{x}{18}=\frac{7}{21}$.

Step-by-Step Solution

Answer

The value of x is 6

Step 1. Given information.

A proportion $\frac{x}{18}=\frac{7}{21}$.

Step 2. Concept used.

We use the cross-product rule.

As $\frac{a}{b}=\frac{c}{d}\Rightarrow ad=bc$ where $a,b$ are two numbers.

Step 3. To find the value of x.

Solve the given proportion

$\begin{array}{l}\frac{x}{18}=\frac{7}{21}\\ \Rightarrow 21x=7\times 18\\ \Rightarrow x=\frac{7\times 18}{21}\\ \Rightarrow x=\frac{18}{3}\\ \Rightarrow x=6\end{array}$

Hence, the value of x is  $6$.