Basic Math and Pre-Algebra Workbook For Dummies, 2nd Edition

Chapter 15

Finding the Right Balance: Solving Algebraic Equations

In This Chapter

Solving simple algebraic equations without algebra

Understanding the balance scale method

Moving terms across the equal sign

Using cross-multiplication to simplify equations

In this chapter, you use your skills in doing the Big Four operations and simplifying algebraic expressions (see Chapter 14) to solve algebraic equations — that is, equations with one or more variables (such as x). Solving an equation means you figure out the value of the variable. First, I show you how to solve very simple equations for x without using algebra. Then, as the problems get tougher, I show you a variety of methods to figure out the value of x.

Solving Simple Algebraic Equations

You don't always need algebra to solve an algebraic equation. Here are three ways to solve simpler problems:

• Inspection: For the very simplest algebra problems, inspection — just looking at the problem — is enough. The answer just jumps out at you.
• Rewriting the problem: In slightly harder problems, you may be able to rewrite the problem so ...