Writing and Evaluating Expressions with Formulas and Variables

The video tutorial explains how to use formulas to write and evaluate algebraic expressions by substituting a given number for a variable. It covers finding the perimeter of a square with a side of 2x, calculating speed as distance divided by time, and determining the area of a square with side 2x. The tutorial emphasizes the importance of correctly substituting values into expressions and formulas.

What is the result when you substitute 5 for x in the expression 3 + x?

• 3

• 5

• 8

• 15

If each side of a square is 2 times x, what is the perimeter when x equals 3?

• 30

• 24

• 18

• 12

How do you calculate speed if you travel 155 miles in t hours?

• Divide 155 by t

• Subtract t from 155

• Multiply 155 by t

• Add 155 to t

What is the area of a square with a side length of 2 times x when x equals 2?

• 12

• 16

• 20

• 8

If t equals 2 hours, what is the speed in miles per hour when traveling 155 miles?

• 76.5

• 75.5

• 77.5

• 74.5