Solving Equations and Inequalities 2.4

2.4 Formulas
a. Evaluate a formula.
b. Solve a formula for a specified variable.

Objective a
Evaluate a formula.

Many applications of mathematics involve relationships among two or more quantities. An equation that represents such a relationship will use two or more letters and is known as a formula.

Example A



Objective b
Solve a formula for a specified variable.

Example B



Example C



Example D



To solve a formula for a given letter, identify the letter and:
1. Multiply on both sides to clear fractions or decimals, if that is needed.
2. Collect like terms on each side, if necessary.
3. Get all terms with the letter to be solved for on one side of the equation and all other terms on the other side.
4. Collect like terms again, if necessary.
5. Solve for the letter in question.

Example E