Answer:
8 units for the length
Step-by-step explanation:
Let l = length
w = width
l = w+3
A = l*w
substitute what we know
40 = (w+3) *w
distribute
40 = w^2 +3w
Subtract 40 from each side
0 = w^2 +3w -40
Factor
0 = (w+8) (w-5)
Using the zero product property
w+8 =0 w-5=0
w= -8 w=5
Since the width cannot be negative
w=5
l = w+3 = 5+3
l = 8 units
