Q59. - Algebra 2

Question

Use cross products to solve each proportion.

$\frac{x}{8}=\frac{3}{4}$

Step-by-Step Solution

Answer

Given proportion is simplified to $x=6$

Step 1 - Cross product between two proportions

Let $\frac{a}{b}$ and $\frac{c}{d}$ be two equal proportions that is $\frac{a}{b}=\frac{c}{d}$

Then cross product is defined as multiplication of denominator of one proportion with the numerator of other proportion, that is $ad=bc$

Step 2 - Substitution

Substitute x for a, 8 for b, 3 for c, and 4 for d into $ad=bc$ gives

$x\times 4=8\times 3$

Step 3 - Simplify x × 4 = 8 × 3

To simplify this expression multiply both the numbers of right side and then divide it from number on the left as shown below.

$\begin{array}{c}4x=24\\ x=\frac{24}{4}\\ x=6\end{array}$