## Evaluate a 2-Variable Expression

### Evaluate Expressions: Learn

A mathematic *expression* is a group of numbers and
operators which can be evaluated to determine their value.

There may be *variables* in the expression which
represent numbers that may or may not be known. A variable
is simply a symbol used as a placeholder for the unknown
number.

If we know the values of the variables, we can find the value of the entire expression.

For example, if x=3 and y=5, then the expression 7x+y-4 can be evaluated in the following way:

7x+y-4 =7*3+5-4 =21+5-4 =22

The very first step where the variables are replaced by their values
is called *substitution*.

### Evaluate Expressions: Practice

#### Evaluate using the given value.

00:00

If x= and y=, then

Press the Start Button To Begin

You have
0
correct and
0
incorrect.

This is
0
percent correct.

### Play

Game Name | Description | Best Score |
---|---|---|

How many correct answers can you get in 60 seconds? | 0 | |

Extra time is awarded for each correct answer.
Play longer by getting more correct. |
0 | |

How fast can you get 20 more correct answers than wrong answers? | 999 |

### Explore

#### Math Lessons by Grade

#### Math Topics

- Addition
- Algebra
- Comparing
- Counting
- Decimals
- Division
- Equations
- Estimation and Mental Math
- Exponents
- Fractions
- Geometry
- Measurement
- Money
- Multiplication
- Naming Numbers
- Patterns
- Percents and Ratios
- Place Value
- Properties
- Statistics
- Subtraction