Question

The width of a rectangle is 16 feet less than 3 times the lenght. If the area is 35 square feet, find the dimensions of a rectangle.

Answer 1

width = 3 x length - 16
w =3l-16
A = lw = l(3l-16)
A = 3l^2-16l
35 = 3l^2 - 16l
3l^2 - 16l - 35 = 0
(3l + 5)(l-7) = 0
3l + 5 = 0
l = -5/3 (not a valid measurement, so not the solution)
or l-7 = 0 and l = 7
length is 7 and width is 3(7)-16=5