Algebra is a mathematical concept that uses numbers as well as letters. The letter or letters in an algebra equation are used to represent an unknown number. This letter in the equation is called a *variable*.

To solve an equation, you use the numbers in the “number sentence” to find the correct solution. For example in the number sentence 6 + x = 15, the variable x stands for an unknown number. In this equation, x equals 9.

In this chapter, the multiplication symbol (×) will be replaced by an asterisk (*) because in algebra, an *x* is used to represent an unknown number.

In algebra, there are instances in an equation when there are numerous operations used—addition, subtraction, multiplication, and/or division. ...

Start Free Trial

No credit card required