##### Basic Math & Pre-Algebra All-in-One For Dummies (+ Chapter Quizzes Online)

Explore Book Buy On AmazonIn algebra, a letter such as *x* that takes the place of a number in one or more equations is called a variable. Practices you need to know about how algebra problems are written:

To add up many of the same variable, count the number of times that variable appears, and then attach that number (called a coefficient) to that variable:

*x*+*x*+*x*+*x*+*x*= 5*x*To multiply many of the same variable, count how many times the variable appears, and then attach an exponent to that variable:

*x*·*x*·*x*·*x*=*x*^{4}Write division problems as fractions:

x ÷ 2 is written as x/2