Answer:
The area of the rectangular area is (1400w-w²) square yards.
Explanation:
Given that,
David has available 2800 yards of fencing. He wants to enclose a rectangular area.
Assume that, the length and width of the rectangular be l and w respectively.
The perimeter of the rectangular area is
=2(length+ width)
=2(l+w)
So,
2(l+w)= 2800
![\Rightarrow l+w= (2800)/(2)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/u6j4yawtazz0qwg021bc9qv0dkgjwqdlpq.png)
![\Rightarrow l+w= 1400](https://img.qammunity.org/2021/formulas/mathematics/middle-school/idwxegtzimeq6tgvpyhwapjek0kfedpe5z.png)
![\therefore l= 1400-w](https://img.qammunity.org/2021/formulas/mathematics/middle-school/k3z62cz901y0gjyiquw7ie9ms1h79ezzib.png)
The area of the rectangular area is = length× width
=l×w
=(1400-w) w
=(1400w-w²) square yards.