13. A rectangular lot has
a river along one side.
River
W
The fencing for the other
3 sides has a total length of 30 m.
When the width of the lot
is w metres, the area of the lot,
in square metres, is expressed
as 30w - 2w².
What is the area of the lot for
each value of w?
a) 5 m
b) 9 m
c) 12 m
1.6