Writing and Evaluating Expressions

A variable text annotation indicator is a letter or symbol that represents a quantity that can change. A constant is a quantity that doesn't change. An algebraic expression is a variable or combination of variables, numbers, and operations.

Examples:

2x

Answer: "2 times x"; 2 is the coefficient and x is the variable

3y+5

Answer: "3 times y plus 5"; 3 is the coefficient, y is the variable, and 5 is the constant

LaTeX: 4h^2-3

Answer: "4 times h to the second power minus 3"; 4 is the coefficient, h is the variable, 2 is the exponent, and 3 is the constant

Consider the expression x² + 5y + 3x + 6.

The variables are x and y
There are 4 terms: x², 5y, 3x, and 6
The terms that involve a variable are variable terms and 6 is a constant
The numbers in front of the variables are called coefficients. The coefficient of x² is 1. The coefficient of 5y is 5. The coefficient of 3x is 3.
The expression is the sum of all 4 terms.

When you evaluate an algebraic expression text annotation indicator , you substitute a number for the variable and find the value.

Sometimes, it's necessary to translate words into math problems. In order to do this, you need to know what words to look for.

Words or Action

Put together or combine

Sum

Find how much more or less

Difference

Put together groups of equal parts

Times

Product

Separate into equal groups

Quotient

Mathematical Operation

Add

Subtract

Multiply

Divide

Examples:

"the sum of 8 and y" translates to "8 + y"
"4 less than x" translates to "x - 4"
"x multiplied by 13" translates to "13x"
"the difference of 5 and y" translates to "5 - y"
"the quotient of 9 more than x and x" translates to "(x + 9)/x"

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