Diana has available 280 yards of fencing and wishes to enclose a rectangular area. ​(a) Express the area A of the rectangle as a function of the width W of the rectangle.
​(b) For what value of W is the area​ largest?
​(c) What is the maximum​ area?

David has 280 yards of fencing to enclose a rectangular area. Find the demensions of the rectangle that maximize the enclosed area.What is the maximum area?

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let x=width

let y=length

2x+2y=280

x+y=140

y=140-x)

Step-by-step explanation:

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1

answer:   rotate 270° clockwise about (7, 1) and reflect across the line x = 7

step-by-step explanation:

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