Question

A rectangle has an area 40 square units. The length is 6 units greater than the width.What are the dimensions?

Answer 1

Length 10, width 4


Work
40 = lw = (6+w)*w
40 = w^2 + 6w
40 + 9 = 49 = w^2 + 6w + 9
49 = (w + 3)^2
7 = w + 3
w = 7-3 = 4

remember that 40 = lw? We now know w, so let's find l:
40 = 4l
l = 40/4 = 10


Length 10 units, width 4 units

Answer 2

10,4

Explanation:

width = w

length =l = w+4

area= l*w = (w+4) * w