Ratios and Proportions

A ratio is a comparison of two quantities by division, expressed as 'a:b' or 'a/b'.

A proportion is an equation that states that two ratios are equal, expressed as 'a/b = c/d'.

Cross-multiply the terms: if $$\frac{a}{b} = \frac{c}{x}$$ , then solve for x using $$x = \frac{b \cdot c}{a}$$ .

Cross-multiplication involves multiplying the numerator of one ratio by the denominator of the other ratio to find an unknown.

x = 10.

Two ratios are equivalent if they represent the same relationship between quantities.

9:12.

Divide both terms of the ratio by their greatest common divisor (GCD).

Ratios can be expressed as fractions, where the first term is the numerator and the second term is the denominator.

a = 10.