Question

6. The polynomial expression x(3x² + 25) (10x² + 4x + 6), where x is in inches, can be used to model the number of cubic inches of cement that will be needed for a new porch. The cement contractor used 2 for the value of x.

Complete the table to determine the dimensions, in inches, of the cement needed for the porch.

Height (shortest length side)


width(medium length side)


length(longest length side) ​

Answer 1

• short: 2 inches
• medium: 37 inches
• long: 54 inches

Explanation:

You want to evaluate the expressions (x), (3x²+25), and (10x²+4x+6) when x=2. These are dimensions in inches.

Evaluation

To evaluate these expressions, put the value where the variable is and do the arithmetic:

• x = 2
• 3x² +25 = 3(2²) +25 = 12 +25 = 37
• 10x² +4x +6 = (10x +4)x +6 = (10·2 +4)·2 +6 = 54

The height is 2 inches; the width is 37 inches; and the length is 54 inches.