SOLUTION: what is the volume of x if the volume of the box is 648 cubic feet, h=8 ft., L=x-7, W=x-7

Algebra.Com
Question 823993: what is the volume of x if the volume of the box is 648 cubic feet, h=8 ft., L=x-7, W=x-7
Answer by algebrahouse.com(1659)   (Show Source): You can put this solution on YOUR website!
Volume of a rectangular prism (or box) is:
V = lwh {length x width x height}

8(x - 7)(x - 7) = 648 {substituted given information into volume formula}
(x - 7)(x - 7) = 81 {divided each side by 8}
x² - 14x + 49 = 81 {used foil method to multiply binomials}
x² - 14x - 32 = 0 {subtracted 81 from each side}
(x - 16)(x + 2) = 0 {factored into two binomials}
x - 16 = 0 or x + 2 = 0 {set each factor equal to 0}
x = 16 or x = -2 {solved each equation for x}
x = 16 {x cannot be negative for x - 7 being the width and length}

the value of x is 16

For more help from me, visit: www.algebrahouse.com





RELATED QUESTIONS

what is the value of x if the volume of the box is 392 cubic feet and the dimensions are: (answered by josgarithmetic)
The base of a rectangular box measures 2 ft by 3 ft. What is the height in feet of the... (answered by rapaljer)
If each cube has a side length of 1unit and volume of one cubic unit ,what is the volume (answered by Elisabeth Elliott)
An oblong box has a volume equal to lwh, where l is the length, w is the width, and h is... (answered by Fombitz)
The length of a rectangular box is 1 inch more than twice the height of the box, and the... (answered by scott8148)
what is the volume of a box that is 8 feet by 7 feet by 4... (answered by edjones)
The volume of a rectangular pool (V =L x W x H) is represented by the expression; V =... (answered by greenestamps)
what is the area of the top of a square box that has a volume of 8 cubic... (answered by ewatrrr)
You are building a wooden sandbox for a local playground. You want tthe volume of the box (answered by reviewermath)