Answer:
The length is 9 units
Step-by-step explanation:
Let x = length
width = x-3
Area = 54 = l*w
54 = x * (x-3)
Distribute
54 = x^2 -3x
Subtract 54 from each side
54-54 = x^2 -3x-54
0 = x^2 -3x-54
Factor
What 2 number multiply to -54 and add to -3
-9 * 6 =54
-9+6 =-3
(x-9) (x+6) =0
Using the zero product property
x=9 x=-6
Since we cannot have negative length
x=9 units
The length is 9 units
