SOLUTION: The perimeter of a rectangle is 35 cm. Express the area, A, of the rectangle as a function of its width, x.

Algebra ->  Rectangles -> SOLUTION: The perimeter of a rectangle is 35 cm. Express the area, A, of the rectangle as a function of its width, x.      Log On


   



Question 214079: The perimeter of a rectangle is 35 cm. Express the area, A, of the rectangle as a function of its width, x.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
A+=+x%2Ay cm2
y+=+A%2Fx
P+=+35 cm
P+=+2x+%2B+2y
2x+%2B+2y+=+35
2y+=+35+-+2x
2%2A%28A%2Fx%29+=+35+-+2x
2A+=+35x+-+2x%5E2
A+=+-x%5E2+%2B+17.5x answer
check answer:
Suppose x+=+12 cm
A+=+-144+%2B+17.5%2A12
A+=+-144+%2B+210
A+=+66 cm2
P+=+2x+%2B+2y
35+=+2%2A12+%2B+2y
2y+=+35+-+24
2y+=+11
y+=+5.5
A+=+xy
A+=+12%2A5.5
A+=+66 cm2
OK