Answer:
P of rectangle = 2(L + W)
21 units = 2(n units + W)
21 units = 2nunits + 2W
21 = 2n + 2W
2W = 21 - 2n
W = 21 - 2n units.
2
on simplifying
10.5 - n units
The width of the rectangle is units (10.5 - n) units.
