Question

Show that the expression for the shaded area (image below) can be written as
a) 2 +5−11

Answer 1

x^2 +5x-11

Explanation:

The area of the large rectangle is (x+4) * (x+1).

FOILing:

x^2 +4x+x+4

x^2 +5x +5:

The area of the unshaded rectangle is 5*3 = 15.

Subtracting the unshaded area from the large rectangle:

x^2 +5x+4 - 15

x^2 +5x-11