The length of a rectangle is 3x+7 .the width is x-4 . express the area of the rectangle in terms of the variable x. a) 3x^2 -5x-28 b) 3x^2 +5x +28 c) 2x^2 +4 x-28 d ) 3x^2 -5x +28

A) 3x²-5x-28. The area of the rectangle  with length 3x+7 and width x-4 can be represented as 3x²-5x-28.

The equation to find the area of the rectangle is simply A = l * w. This means that the area of a rectangle is equal to the product of its length (l) by its width (w), or of its length by its width.

A = w*l

A = (3x + 7)(x -4) = (3x)(x) + (3x)(-4) + (7)(x) + (7)(-4)

A = 3x² - 12x + 7x - 28

A = 3x² -5x - 28

step-by-step explanation:

circumference divided by 3.141592654 then timesthe radius twice