[B]Problem:
A farm has a perimeter of 55 km and has an area of 150 km sq. Find the dimensions of the farm.
i tried to answer on this that
A= l x w P = 2 (l + w)
150 km sq. = l x w 55 km = 2 (l +w)
what is next to here? do i need to manipulate the formula? i'm stuck here.
Please does anybody can help me on this?
Thank you
2(150/w + w) = 55
2(150+w^2w) = 55
(300+ 2w^2) / w = 55
300+ 2w^2 = 55w
2w^2 - 55w + 300 = 0
(2w - 15 ) ( w - 20) = 0
w = 20 or w = 15/2 or 7.5
LW = 150 if w = 20
L = 150/20
L = 7.5
LW = 150 if w = 7.5
L = 150/7.5
L = 20
which of this two values is right/ correct for the L ?
2(150/w + w) = 55
2(150+w^2/w) = 55
(300+ 2w^2) / w = 55
300+ 2w^2 = 55w
2w^2 - 55w + 300 = 0
(2w - 15 ) ( w - 20) = 0
w = 20 or w = 15/2 or 7.5
LW = 150 if w = 20
L = 150/20
L = 7.5
LW = 150 if w = 7.5
L = 150/7.5
L = 20
which of this two values is right/ correct for the L ?