Algebra I All-in-One For Dummies

Chapter 20

Facing Up to Formulas

IN THIS CHAPTER

Finding comfort in familiar formulas

Introducing perimeter, area, and volume formulas

Computing interest and percentages

Counting on permutations and combinations

Just as a cook refers to a recipe when preparing delectable concoctions, algebra uses formulas to whip up solutions. In the kitchen, a cook relies on the recipe to turn equal amounts of jalapeños, cream cheese, and beans into a zippy dip. In algebra, a formula is an equation that expresses some relationship you can count on to help you concoct such items as the diagonal distance across a rectangle or the amount of interest paid on a loan.

Formulas such as , , and are much more compact than all the words needed to describe them. And as long as you know what the letters stand for, ...