This tutorial explains how to evaluate variable expressions involving integers. It covers the concept of variables as unknowns in mathematical expressions and demonstrates the process of substitution and simplification, often referred to as 'plug and chug'. The video provides several examples, including expressions with single and multiple variables, handling negative values, and recognizing simplification patterns. Each example is broken down step-by-step, emphasizing the order of operations and the importance of correctly substituting values into variables.

What is a variable in a mathematical expression?

• A constant value

• A mathematical operation

• A known number

• An unknown letter

What is the first step in evaluating an expression with variables?

• Divide all numbers

• Add all numbers

• Multiply all numbers

• Substitute values into variables

What does the phrase 'plug and chug' refer to?

• Adding numbers

• Substituting and simplifying

• Dividing numbers

• Subtracting numbers

In the expression 5t + 3, if t = 8, what is the simplified result?

• 48

• 43

• 40

• 35

What operation is implied when a number is next to a variable?

• Multiplication

• Division

• Subtraction

• Addition

What is the importance of following the order of operations?

• It ensures the correct result

• It makes calculations faster

• It only applies to addition

• It is not important

In the expression XY - Y + 3X, if X = 3 and Y = 2, what is the simplified result?

• 11

• 13

• 15

• 9

When substituting values, what should you ensure with multiple variables?

• Use the same value for all variables

• Plug in the correct value for each variable

• Ignore the variables

• Use only positive values

What is the result of 3 times 2?

• 8

• 7

• 6

• 5

What is the result of 3 times 3?

• 8

• 9

• 7

• 6