Problema Solution
The length of a rectangle is 5m more than twice its width, and the area of the rectangle is 63m^2 . Find the dimensions of the rectangle.
Answer provided by our tutors
let the length be l and the width be w.
the length is 5 for than twice the width so you have the equation:
l = 2w + 5
the area, length*width, is 63, so you have:
w*l= 63
substitute the equation for l
w(2w+5) = 63 solve for w
2w2+5w = 63 get the equation to equal zero so you can factor and solve
2w2+5w-63 = 0 now factor
(2w-9)(w+7) = 0 set each part equal to zero and solve for w
2w - 9 = 0
2w = 9
w = 9/2 = 4.5
or
w+7 = 0
w = -7 width can't be negative so use the first result
w = 4.5
substitute this into the equation for l
l = 2w+5
l = 2(4.5) + 5
l = 9+5
l = 14
so the length is 14m and the width is 4.5m