Easy Algebra Step-by-Step

Algebraic Expressions 65

Solution

a.

5

9

() 32 , where F is the number of degrees Fahrenheit

Step 1. Recall that a letter names a variable whose value may vary.

Step 2. Name the variable(s).

The letter F stands for the number of degrees Fahrenheit and can be

any real number, and so it is a variable.

Step 3. Recall that a constant has a fi xed, defi nite value.

Step 4. Name the constant(s).

The numbers

5

9

and 32 have fi xed, defi nite values that do not change,

and so they are constants.

b. πd, where d is the measure of the diameter of a circle

Step 1. Recall that a letter names a variable whose value may vary.

Step 2. Name the variable(s).

The letter d stands for the measure of the diameter of a circle and

can be any nonnegative number, and so it is a variable.

Step 3. Recall that a constant has a fi xed,

defi nite value.

Step 4. Name the constant(s).

The number π has a fi xed, defi nite

value that does not change, and so it is

a constant.

If there is a number immediately next to a variable (normally preced-

ing it), that number is the numerical coeffi cient of the variable. If there is

no number written immediately next to a variable, it is understood that the

numerical coeffi cient is 1.

Problem What is the numerical coeffi cient of the variable?

a. –5x

b. y

c. πd

Even though the number pi is

represented by a Greek letter, π is not a

variable. The number π is an irrational

number whose approximate value to

two decimal places is 3.14.