you have 160 yards of fencing material. if you want to construct a rectangular pen whose width is between 10 and 20 yards, inclusive, what is the longest that such a pen can be, in yards?

Respuesta :

Answer:

70 yards

Step-by-step explanation:

we know that

The perimeter of the rectangular pen is equal to

[tex]P=2(L+W)[/tex]

we have

[tex]P=160\ yd[/tex]

The width is between 10 and 20 yards inclusive

we know that

The longest pen will be for the smaller value of W

so

For W=10 yd

substitute in the equation of perimeter

[tex]160=2(L+10)[/tex]

solve for L

[tex]L+10=80\\L=80-10\\L=70\ yd[/tex]