ATI TEAS GUIDE TO MATH | ALGEBRAIC EQUATIONS -

UNDERSTANDING ALGEBRAIC EQUATIONS

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Now comes the nitty gritty of mathematics. Understanding algebraic equations. The ATI TEAS will test the applicant’s ability to simplify equations and solve operations with unknown quantities.

HOW TO SIMPLIFY EQUATIONS

One of the easiest ways to solve algebraic equations is to combine like terms. Like terms is described as terms that contain the same variables (or no variables at all) raised to the same power.

For example: (x2 + 4x +1) + (2×2 + x + 8)

In order to simplify the expression, we must combine like terms. For example, x2 and 2x2 are like terms. They both contain the same variable x raised to the second power (x2). In addition, 4x and x are also like terms because neither has an exponent. Lastly, 1 and 8 are like terms because neither contains a variable. We can combine each set of like terms.

(x2 + 4x +1) + (2×2 + x + 8) = x2 + 2×2 + 4x + x + 1 + 8

= (x2 + 2×2) + (4x + x) + (1 + 8)

= 3×2 + 5x + 9

HOW TO USE THE FOIL METHOD TO MULTIPLICATION

FOIL expressions require the applicant to multiply two binomials. Binomials are defined as equations that contain two same terms. FOIL is primarily used with multiplication of these binomials.

For example: (x + 2) (2x + 4)

FOIL stands for First, Outer, Inner, and Last. This is the order in which we multiple the binominals.

First, we multiple the first two terms of each binomial.

Multiply x by 2x = 2×2

Next, multiply the outer two terms of each binomial.

Multiply x by 4 = 4x

Next, multiply the inner two terms of each binomial.

Multiply 2 by 2x = 4x

Next, multiply the last two terms of each binomial.

Multiply 2 by 4 = 8

Lastly add the results together.

2×2 + 4x + 4x + 8 = 2×2 + 8x + 8

HOW TO SOLVE VARIABLE EQUATIONS

Algebraic equations can become confusing once they involve one unknown variable. This variable is usually represented by the letter x or y. These equations test the applicant’s ability to find the unknown variable.

For example: 3x + 6 = 9

In order to solve these equations, we must isolate the variable on side of the equation. We begin by subtract 6 from both sides of the equal sign. *It’s important to note that what is done on one side of the equal sign is also completed on the other side of the equal sign.

3x + 6 = 9

3x + 6 – 6 = 9 – 6

3x + 0 = 3

3x = 3

Now we divide both sides by 3 to isolate the variable.

3x = 3

x = 1

The value for x is 1.

HOW TO SOLVE INEQUALITY EQUATIONS

Inequalities equations express the relationship between two quantities where one quantity may be greater or less than the other.

Examples of Inequality Symbols

> greater than

< less than

greater than or equal to

less than or equal to

Inequality equations are solved the same way as equations with the exception of one thing. When multiplying or dividing both sides of an inequality by a negative number, you must reverse the direction of the inequality sign.

For example: -3x > 9

In order to solve this equation, we must isolate the variable x on one side of the equation.

3x > 9

** notice the sign change

x < -3

UNDERSTANDING ABSOLUTE VALUE EQUATIONS

The absolute value of a number is the distance that number lies from zero on a number line. Absolute value equations are indicated by two vertical bars:

For example: |X| = 6

If the absolute value of x is equal to 6, then x must lie exactly 6 units away from zero on the number line. This means that x can be either positive (6) or negative (-6). Both 6 and -6 lie exactly 6 units away from zero. Here is another equation example:

|X – 3| = 6

This equation is slightly different. We understand that the absolute value of X – 3 is 6. This informs us that the quantity X – 3 lies equally 6 units away from zero. Meaning, X – 3 could equal 6 or -6. We will set up our equations to solve both possibilities.

X – 3 = 6

X – 3 + 3 = 6 +3

X = 9

X – 3 = – 6

X – 3 + 3 = –6 + 3

X = – 3

The value for X is either 9 or – 3. We set this values in notations, such as {9, –3}.