Question 81296
Remember that the volume of a rectangular prism (a box) is given by:
{{{V = L*W*h}}}
In this case, you have:
L = x inches.
W = 2x inches.
h = (3x-5) inches.So the volume of the box in your problem can be expressed by the function:
{{{V(x) = x(2x)(3x-5)}}} or
{{{V(x) = 6x^3-10x^2}}} so...
{{{V(3) = 6(3)^3-10(3)^2}}}
{{{V(3) = 6(27)-10(9)}}}
{{{V(3) = 162-90}}}
{{{V(3) = 72}}}cubic inches.