A farmer makes a rectangular enclosure for his animals.
He uses a wall for one side and a total of 72 metres of fencing for the other three sides.
The enclosure has width x metres and area A square metres.
(a) Show that A = 72x – 2x^2

Question

A farmer makes a rectangular enclosure for his animals.
He uses a wall for one side and a total of 72 metres of fencing for the other three sides.
The enclosure has width x metres and area A square metres.
(a)	Show that A = 72x – 2x^2

anonymous · Answer

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anonymous · Answer

perimeter of enclosure=2(x+lenght of wall)=72-lenght of wall
2x+2l=72-l
3l=72-2x
l=72-2x/3
area A=x*lenght of wall
A=x(72-2x)/3
A=(72x-2x^2)/3

anonymous · Answer

oh wow ok so u cant really get x unless u're given the measurements rite?