The answer is C
Explanation; there are 2 triangles and 3 rectangles
It looks like the differential equation is
Factorize the right side by grouping.
Now we can separate variables as
Integrate both sides.
You could go on to solve for 
explicitly as a function of 
, but that involves a special function called the "product logarithm" or "Lambert W" function, which is probably beyond your scope.
Answer:
3.1
Step-by-step explanation:
Since this is area and you are given the width must divide area by width ( A/W = L) 13.02 divided by 4.2 = 3.1. You can check this by doing 3.1 multiplied by 4.2. It should give you 13.02
It would be bout 2.50 for on issue. Hope that helped
