Answer:
w=6
l=14
Step-by-step explanation:
Area of rectangle = l*w
So:
[tex]w*(w+8)=84[/tex]
Then, just find w, and w+8.
[tex]w^2+8w=84\\w^2+8w-84=0\\(w-6)(w+14)=0\\w-6=0, w=6\\w+14=0, w=-14[/tex]
Length cannot be negative, so the width is 6.
Length = width + 8 = 6+8=14
