Answer:
Part A: To find the expression for the length of the rectangular space, we can use the formula for the area of a rectangle, which is length multiplied by width. We have the expression for the area as 8x² - 12x, and the expression for the width as 4x. So, we can write:
Area = Length × Width
8x² - 12x = Length × 4x
Simplifying the right side by multiplying, we get:
8x² - 12x = 4x × Length
2x² - 3x = Length
Therefore, the expression for the length of the rectangular space is 2x² - 3x.
Part B: To prove that the expression for the length from Part A is correct, we can multiply it by the expression for the width and simplify:
Length × Width = (2x² - 3x) × (4x)
= 8x³ - 12x²
= 4x(2x² - 3x)
= 4x(2x(x - 3))
This is in fact the same as the expression for the area of the rectangular space, 8x² - 12x, in standard form.