# How do you solve E/7=10/14?

Jan 10, 2017

You use: $\frac{A}{B} = \frac{C}{D} \leftrightarrow A \cdot D = B \cdot C$ (cross-multiply)

#### Explanation:

$\to E \cdot 14 = 7 \cdot 10 \to E = \frac{7 \cdot 10}{14} = \frac{\cancel{7} \cdot \cancel{2} \cdot 5}{\cancel{2} \cdot \cancel{7}} = 5$

Check : $\frac{5}{7} = \frac{10}{14}$

Jan 10, 2017

Move all of the constants to one side of the equation with algebraic operations just as with and equality.

#### Explanation:

$\left(\frac{E}{7}\right) \cdot 7 = \left(\frac{10}{14}\right) \cdot 7$

$E = \left(\frac{10}{2}\right)$ ; E = 5

CHECK: $\left(\frac{5}{7}\right) = \left(\frac{10}{14}\right)$ ; $\left(\frac{5}{7}\right) \cdot \left(\frac{2}{2}\right) = \left(\frac{10}{14}\right)$

$\left(\frac{10}{14}\right) = \left(\frac{10}{14}\right)$ Correct.