Question

The area of a rectangle is x^2-2x-15 and the length of the rectangle is x+3

a. find the width of the rectangle
I figured this one out, it's x-5. Just to help you guys out.

b. find the area of the rectangle if the width is 6 feet.

Answer 1

if the width is 6 feet then an equation for this could be x-5=6.
by solving this equation, you'll see that x=11.
if x=11 then the length would be 11+3 which is 14.
the area of a rectangle is length times width.
we know that the width is 6 and the length is 14
6*14=84
area=84 feet