Now, we’ll review the algebra topics covered in the Math IC Subject Test.

 

 

    There are a number of algebraic terms you should know in order to be able to talk and think about algebra:

• Variable. An unknown quantity, written as a letter. The letters x and y are the most commonly used letters for variables, but a variable can be represented by any letter in the English alphabet. Greek letters are also used quite often. Variables will sometimes represent specified quantities, like apples or dollars, for example. Other times, a specific meaning won’t be attached to them. You’ll need to manipulate variables just to show that you understand certain algebraic principles.
• Constant. A quantity that does not change. In other words, a number.
• Term. The product of a constant and a variable. Another way to define a term is as any quantity that is separated from other quantities by addition or subtraction. For example, in the equation below, the left side contains four terms {x³, 2x², –7x, 4} and the right side contains two terms {x, –1}. The constants, 4 and –1, are considered terms because they are considered coefficients of variables raised to the zero power. For constant 4, 4 = 4x⁰. So every term, including constants, is the product of a constant and a variable raised to some power.
   
• Expression. Any combination of terms. An expression can be as simple as a single constant term, like 5. Or an expression can be as complicated as the sum or difference of many terms, each of which is a combination of constants and variables, such as {(x² + 2)³ – 6x} ⁄ 7x⁵. Expressions don’t include an equal sign, which is what differentiates expressions from equations. Expressions therefore cannot be solved; they can only be simplified.
• Equation. Two expressions linked by an equal sign. A lot of the algebra that you’ll have to perform on the SAT II Math tests will consist of solving an equation with one variable. Most of this chapter, in fact, deals with different techniques for simplifying expressions and solving different types of equations. First, we’ll review how to write an equation.