Evaluating Algebraic Expressions

Mrs. Feld introduces evaluating algebraic expressions by substituting variables with given values. She provides examples using different variables (X, N, Y, K, S) and demonstrates the process of substitution and solving using order of operations. The video encourages students to pause and try solving expressions independently before revealing the solutions.

What is the first step in evaluating an algebraic expression?

• Substitute the variable with a given value

• Add all numbers together

• Divide the expression by 2

• Multiply all terms

If X = 15, what is the result of the expression X - 5?

• 5

• 10

• 15

• 20

When n = 8, what is the result of the expression n - 6?

• 2

• 6

• 4

• 8

What is the result of the expression 2y + 5 when y = 3?

• 10

• 11

• 9

• 8

How do you multiply a whole number by a fraction?

• Divide the whole number by the fraction

• Add the whole number to the fraction

• Convert the whole number to a fraction and multiply

• Multiply the whole number by the numerator and keep the denominator

What is the result of 6 * K when K = 1/3?

• 1

• 4

• 3

• 2

What operation should be performed first according to the order of operations?

• Addition

• Subtraction

• Multiplication

• Division

If S = 2, what is the result of the expression 3S + 1?

• 5

• 6

• 7

• 8

What is the result of 4n when n = -2?

• -8

• 8

• -4

• 4

What is the final result of the expression 4n - 4 when n = -2?

• 8

• -8

• 12

• -12