## Key Concepts

**Solve an application.**- Identify what you are asked to find and choose a variable to represent it.
- Write a sentence that gives the information to find it.
- Translate the sentence into an equation.
- Solve the equation using good algebra techniques.
- Write a complete sentence that answers the question.
- Check the answer in the problem and make sure it makes sense.

**Find percent increase.**- Find the amount of increase:[latex]\text{increase}=\text{new amount}-\text{original amount}[/latex]
- Find the percent increase as a percent of the original amount.

**Find percent decrease.**- Find the amount of decrease.[latex]\text{decrease}=\text{original amount}-\text{new amount}[/latex]
- Find the percent decrease as a percent of the original amount.

## Glossary

**percent increase**- The percent increase is the percent the amount of increase is of the original amount.

**percent decrease**- The percent decrease is the percent the amount of decrease is of the original amount.