Evaluating Expressions with Substitution

The video tutorial explains how to evaluate mathematical expressions by substituting the variable x with the number 6. It covers four expressions: x + 2, 2x, x squared, and 2 raised to the power of x. The tutorial emphasizes the importance of using parentheses during substitution to ensure correct evaluation, especially when dealing with negative numbers or exponents. Each expression is evaluated step-by-step, demonstrating the process of substitution and calculation.

What is the first step in evaluating an expression when x equals a specific value?

• Add the value to x

• Multiply the value by x

• Subtract the value from x

• Substitute the value for x

What is the result of the expression x + 2 when x is substituted with 6?

• 10

• 8

• 12

• 6

How do you evaluate the expression 2x when x equals 6?

• Add 2 to 6

• Multiply 2 by 6

• Subtract 2 from 6

• Divide 6 by 2

What is the value of 2x when x is 6?

• 12

• 8

• 14

• 10

Why are parentheses important when evaluating x^2 if x is negative?

• They are not important

• They simplify the expression

• They help in addition

• They ensure the correct base is used

What is the result of x^2 when x is substituted with 6?

• 42

• 36

• 30

• 48

How many factors of 2 are there in the expression 2^x when x is 6?

• 5

• 4

• 6

• 7

What is the value of 2^x when x is 6?

• 48

• 32

• 72

• 64

Which of the following is a faster way to calculate 2^6?

• Subtract 2 from 64

• Add 2 six times

• Recognize 2^3 as 8 and multiply 8 by 8

• Multiply 2 by 6