Order of Operations and Substitution

The video tutorial explains how to solve mathematical expressions using the order of operations (PEMDAS) and substitution of variables. It demonstrates solving an expression by substituting a value for a variable and following the correct order of operations. The tutorial also covers evaluating another expression by substituting a given value and applying PEMDAS to reach the solution.

What is the first step in solving an expression using the order of operations?

• Multiply and divide from left to right

• Add and subtract from left to right

• Substitute variables with numbers

• Solve inside parentheses first

When substituting a value for X in the expression 15X - 5X, what operation is performed first?

• Subtraction

• Division

• Multiplication

• Addition

If X is replaced with 10 in the expression 15X - 5X, what is the result of 15 times 10?

• 200

• 100

• 150

• 50

After substituting X with 10 in 15X - 5X, what is the final result after subtraction?

• 100

• 50

• 104

• 140

In the expression 7 times the sum of 8 and 2B, what should be done first?

• Multiply 2 by B

• Substitute B with a number

• Add 8 and 2

• Multiply 7 by 8

What is the value of 2B when B is replaced with 6?

• 10

• 8

• 12

• 14

After substituting B with 6 in the expression 7 times (8 + 2B), what is the result of 8 + 12?

• 18

• 24

• 22

• 20

What is the final result of 7 times (8 + 2B) when B is 6?

• 130

• 140

• 120

• 150

What is the invisible operation between 7 and the parentheses in the expression 7(8 + 2B)?

• Multiplication

• Division

• Subtraction

• Addition

What is the result of 7 times 20?

• 150

• 120

• 130

• 140