The video tutorial explains the concept of variables as unknowns in expressions and demonstrates how to evaluate expressions by assigning values to these variables. It covers the absolute value function, emphasizing its property of always yielding a positive result. The tutorial also discusses the importance of following the order of operations, using the PEMDAS rule, to correctly solve mathematical expressions.

What is the primary purpose of using variables in mathematical expressions?

• To make calculations easier

• To confuse students

• To represent unknown values

• To avoid using numbers

When evaluating an expression, what is the first step you should take?

• Divide the expression by 2

• Multiply all terms

• Assign values to variables

• Add all numbers together

What does a double negative in an expression result in?

• A positive value

• A negative value

• Zero

• An undefined value

How is the absolute value of a number best described?

• The square of the number

• The negative of the number

• The distance from zero

• The number itself

What is the result of the expression 4 + 11 / 2?

• 5.5

• 15/2

• 7.5

• 8

In the order of operations, which should be performed first?

• Subtraction

• Multiplication

• Operations inside parentheses

• Addition

What is the square of -11?

• -121

• 121

• 0

• 11