Q:

please help 10 pointsThe height and width of a rectangular prism are each 2 inches shorter than the length of the prism. The volume of the prism is 40 cubic inches. Approximate the dimensions of the prism to the nearest hundredth. Show work.

Accepted Solution

A:
Answer:The length of the prism is 4.87 inchesThe width of the prism is 2.87 inchesThe height of the prism is 2.87 inchesStep-by-step explanation:Letl -----> the length of the prism in inchesw ----> the width of the prism in inchesh---> the height of the prism in incheswe know thatThe volume of the prism is [tex]V=lwh[/tex] we have[tex]V=40\ in^3[/tex]so[tex]40=lwh[/tex] -----> equation A[tex]w=l-2[/tex] ----> equation B[tex]h=l-2[/tex] -----> equation Csubstitute equation B and equation C in equation A and solve for l[tex]40=l(l-2)(l-2)\\\\40=l(l^{2}-4l+4)\\\\40=l^{3}-4l^{2}+4l\\\\l^{3}-4l^{2}+4l-40=0[/tex]Solve the cubic equation by graphingusing a graphing toolThe solution is l=4.87 insee the attached figureFind the value of w[tex]w=4.87-2=2.87\ in[/tex] [tex]h=4.87-2=2.87\ in[/tex] The approximate dimensions of the prism areThe length of the prism is 4.87 inchesThe width of the prism is 2.87 inchesThe height of the prism is 2.87 inches