Given data:
The expression for the length of the rectanngle is L=B+5.
The given area of the rrectangle is A=84 cm^2.
The expression for the area of the rectangle is,
A=LxB
Substitute the given values in the above expression.
84=(B+5)(B)
B^(2)+5B-84=0
B^(2)+12B-7B-84=0
B(B+12)-7(B+12)=0
(B+12)(B-7)=0
B=7 cm
The lenght of the rectangle is,
L=7CM+5cm
=12 cm.
Thus, the lenght of the rectangle is 12 cm, and width of rectangle is