Question

A basketball court is in the shape of a rectangle. It has a length of (x − 7) meters and a width of (x + 3) meters. The expression below represents the area of the court in square meters:

(x − 7)(x + 3)

Which of the following simplified expressions represents the area of the basketball court in square meters?

− 6x + 3
x2 − 21
x2 − 4x − 21
x2 − 7x + 3

Answer 1

(x - 7)(x + 3) = x^2 + 3x - 7x - 21 = x^2 - 4x - 21 <=

Answer 2

The answer is x² - 4x - 21 or C

The area (A) of the rectangle is:

A = l * w                     (l - length, w - width)

We have:

l = x - 7

w = x + 3

Therefore:

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

Now, multiply each factor with another:

A = (x - 7)(x + 3) = x * x + x * 3 - 7 * x - 7 * 3 = x² + 3x - 7x - 21 = x² - 4x - 21