Question

Which of the following represents the area of a rectangle whose length is 5x + 7 and whose width is
x – 4?

5x2 – 28

5x2 – 13x – 28

5x2 + 13x – 28

5x2 + 28

Answer 1

Do you know the formula for the area of a rectangle?

Answer 2

5x^2 - 13x - 14

considering that area of rectangle is length times width

Answer 3

area = l x w
(5x + 7 )(x – 4)

Answer 4

\[A = lw\]\[A = (5x + 7)(x - 4)\]\[A = 5x(x - 4) + 7(x - 4)\]\[A = ?\]For this, you basically use the formula for a rectangle which is at the top. Then, I FOILed the binomials.