McGraw Hill Glencoe Algebra 2, 2012
MH
McGraw Hill Glencoe Algebra 2, 2012 View details
Mid-Chapter Quiz
Continue to next subchapter

Exercise 7 Page 340

Think about the formula for the volume of a rectangular prism.

C

Practice makes perfect

To find the area of the base, we need to consider the formula for volume of a rectangular prism. V= B * h, where Bis the area of the base We know that the height h is given as x+3. We are also given that the volume of the rectangular prism V is 6x^3+19x^2+2x-3.

Given our formula for the volume, we know that the product of our height x+3 and the expression for the base should equal our volume of the rectangular prism. Let's multiply our height by each of the possible expressions for the base to check which one works. Let's begin with option A.

V ? = B * h
6x^3+19x^2+2x-3 ? = ( 6x^4+37x^3+59x^2+3x-9) * ( x+3)
6x^3+19x^2+2x-3 ? = x(6x^4+37x^3+59x^2+3x-9)+3(6x^4+37x^3+59x^2+3x-9)
6x^3+19x^2+2x-3 ? = 6x^5+37x^4+59x^3+3x^2-9x+3(6x^4+37x^3+59x^2+3x-9)
6x^3+19x^2+2x-3 ? = 6x^5+37x^4+59x^3+3x^2-9x+18x^4+111x^3+177x^2+9x-27
6x^3+19x^2+2x-3 ≠ 6x^5+55x^4+170x^3+180x^2-27 *

Because the product did not equal the volume, we know that option A is incorrect. In a similar way, we can check options B, C, and D.

Options B * h Product Equal to V?
B ( 6x^2+x+1)( x+3) 6x^3+19x^2+4x+3 No
C ( 6x^2+x-1) ( x+3) 6x^3+19x^2+2x-3 Yes
D ( 6x+1) ( x+3) 6x^2+19x+3 No

After multiplying the choices, we can see that the base is equal to the expression in option C.