The diagram shows a cuboid of volume Vcm (cubed)? (a) Show that V = 15 + 16x-x(squared) - 2x (cubed)

see explanation

Step-by-step explanation:

The volume (V) of the cuboid is calculated as

V = (2x + 5)(3 - x)(x + 1)

   = (3 - x)(2x + 5)(x + 1) ← expand the pair of factors using FOIL

    = (3 - x)(2x² + 7x + 5)

    = 3(2x² + 7x + 5) - x(2x² + 7x + 5) ← distribute parenthesis

    = 6x² + 21x + 15 - 2x³ -7x² - 5x ← collect like terms and rearrange

    = 15 + 16x - x² - 2x³

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

answer:

f(5/2) = 10/3

i hope this you!