A shed has dimensions of 12m in length and 5 m in width. Both the length and width are "increased by the same amount" in order to increase the floor area by "more than double" the original area. What is the amount of the increase in length?
original area = 60 m^2
new length = 12+x
new width = 5+x
new area = (12+x)(5+x) = 120 , double the original
60 + 17x + x^2 = 120
x^2 + 17x - 60 = 0
(x + 20)(x-3) = 0
x = 3, or x = -20, but we can't have a negative side
x = 3
So to have an new area of more than 120 , we need
x > 3