It will change from having a value of 7,000 to having a value of 70
If the width is w and the length is l, then 2w-2=l and 2w+2l=72 (using the perimeter equation). Plugging 2w-2 in for l, we get 2w+(2w-2)*2=72 and 6w-4=72. Adding 4 to both sides, we get 6w=76. After that, we divide both sides by 6 to get 74/6=w. Since l=2w-2=136/6, we get (136/6)(74/6)=656.75=area
It will take her 8 weeks to save up enough money for the bike.
To get the answer first you have to subtract 125 from 245 to see how much money she still has to save then divide the answer which is 120 by 15 and you get 8. Hope this helps!!
Parameterize the lateral face

of the cylinder by

where

and

, and parameterize the disks

as


where

and

.
The integral along the surface of the cylinder (with outward/positive orientation) is then



