# How do you solve proportions?

Jun 3, 2018

Solving proportions is like solving fractions:

$a : b \to c : d$ can be rewritten as $\frac{a}{b} = \frac{c}{d}$ and now you can solve for any of the variables.

See an example below:

#### Explanation:

3 to 4 is like what to 16?

This can be rewritten as a proportion:

$3 : 4 \to c : 16$

Which can be rewritten as:

$\frac{3}{4} = \frac{c}{16}$

Which can be solved as:

$\textcolor{red}{16} \times \frac{3}{4} = \textcolor{red}{16} \times \frac{c}{16}$

$\cancel{\textcolor{red}{16}} \textcolor{red}{4} \times \frac{3}{\textcolor{red}{\cancel{\textcolor{b l a c k}{4}}}} = \cancel{\textcolor{red}{16}} \times \frac{c}{\textcolor{red}{\cancel{\textcolor{b l a c k}{16}}}}$

$12 = c$

$c = 12$

3 to 4 is like 12 to 16?