Using Rates, Ratios, and Proportions

New Concept Algebra is built on relationships between quantities. A core example is the proportion, an equation that shows two ratios are equal.

Proportion: The equation $\frac{a}{b} = \frac{c}{d}$ is a proportion.

Cross Products Property: If $\frac{a}{b} = \frac{c}{d}$ and $b \ne 0$ and $d \ne 0$, then $ad = bc$. What’s next Our journey begins with this lesson on rates, ratios, and proportions. Soon, you'll use these fundamental tools to practice setting up and solving your first algebraic equations.