Algebra Homework help

Question

Question: You have a rectangular prism ( with square bases) of cheese. You slice it diagonally in half. The length of the cheese is represented by the equation -5x2+3x+2=0. You also know that the length is a whole. The height of the cheese is 4 times the length. What is the area & perimeter of the cheese? 

Answer 1

Area = length * width

Perimeter = 2l + 2w

length = -5x² + 3x + 2

height = 4*length = 4(-5x² + 3x + 2) = -20x² + 12x + 8

width = height (square bases)

Area = ( -5x² + 3x + 2)( -20x² + 12x + 8 )

= 100x⁴ - 60x³ - 40x² - 60x³ + 36x² + 24x - 40x² + 24x + 16

= 100x⁴ - 120x³ - 44x² + 48x + 16

Perimeter = 2(-5x² + 3x + 2) + 2(-20x² + 12x + 8)

= -10x² + 6x + 4 - 40x² + 24x + 16

= -50x² + 30x + 20