Evaluating Expressions with Substitution

The video tutorial demonstrates how to evaluate the expression 3x^2 - 8x + 7 when x is -2. It begins by substituting -2 for x in the expression, then proceeds through the calculation steps, explaining each operation. The tutorial emphasizes the importance of handling negative numbers correctly, particularly when squaring them. The final result of the expression is calculated to be 35.

What is the first step in evaluating the expression 3x squared minus 8x plus 7 when x is negative 2?

• Add 7 to x

• Substitute x with negative 2

• Square the expression

• Multiply 3 by x

What is the result of squaring negative 2?

• Negative 4

• Positive 4

• Negative 2

• Positive 2

How do you handle the term -8 times negative 2 in the expression?

• Subtract 16

• Add 16

• Multiply by 2

• Divide by 2

What is the result of 3 times 4 in the expression?

• 28

• 12

• 7

• 16

What is the final result of the expression after all calculations?

• 12

• 35

• 28

• 16