Question

Use the figure shown to the
right to write a polynomial
that represents the areatof
the shaded region. Express
the polynomial in standard
form, that is, in descending
powers of x.

The polynomial that represents the area of the shaded region is ]
(Simplify your answer. Type your answer in standard form.)

Answer 1

Answer:

4x + 16

Step-by-step explanation:

The area of the shaded region = area of the outer rectangle - area of the inner rectangle

Area of rectangle = l*w

Area of outer rectangle, where length (l) = (x + 5), and width (w) = (x + 4):

Area = (x + 5)(x + 4)

Expand

x(x + 4) +5(x + 4)

x² + 4x + 5x + 20

area of outer rectangle = x² + 9x + 20

Area of inner rectangle, where length (l) = (x + 4), and width (w) = (x + 1):

Area = (x + 4)(x + 1)

Expand

x(x + 1) +4(x + 1)

x² + x + 4x + 4

Area of inner rectangle = x² + 5x + 4

Area of shaded region = (x² + 9x + 20) - (x² + 5x + 4)

x² + 9x + 20 - x² - 5x - 4

Collect like terms together

x² - x² + 9x - 5x + 20 - 4

4x + 16

Area of the shaded region = 4x + 16