Evaluating Expressions with Variables

Evaluate the expression 6g + 4 when g = 3.

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Evaluate the expression 2f - 3 when f = 8.

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What is an expression in mathematics?

• A combination of numbers, variables, and operators that represents a value.

• A single number without any operations.

• A statement that can be true or false.

• A method to solve equations.

How do you substitute a variable in an expression?

• Replace the variable with its given value in the expression.

• Add the variable to the expression.

• Multiply the variable by a constant.

• Ignore the variable in the expression.

What is the order of operations used in evaluating expressions?

• Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right)

• Addition, Subtraction, Multiplication, Division, Exponents, Parentheses

• Multiplication, Division, Addition, Subtraction, Parentheses, Exponents

• Exponents, Parentheses, Addition, Subtraction, Multiplication, Division

Evaluate the expression 5x - 4 when x = 6.

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Evaluate 3x² if x = 5.

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Evaluate the expression 4m + 7 when m = 2.

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What is a variable in an expression?

• A symbol that represents a known value in an expression or equation.

• A number that does not change in an expression.

• A symbol, often a letter, that represents an unknown value in an expression or equation.

• A constant that is used to define a function.

What is the result of squaring a number?

• It means adding the number to itself.

• It means multiplying the number by itself.

• It means subtracting the number from itself.

• It means dividing the number by itself.