Ok the surface area is 2lw+ 2lh + 2wh because that is the sum of all the surfaces
You get 96 + 96 + 72 mm^2
The second one is correct
Answer: 4% per year
The explanation is in the picture.
We have been given a system of nonlinear equations.

In order to solve this system we can first equate the two equations in order to get a quadratic in x.

Our next step is to bring all the terms on one side.

Now we have to solve this equation. We can solve it by factoring using the splitting middle term method.



Upon setting each of these factors equal to zero using zero product property we get

Upon solving both these equations we get

Now we can substitute these values of x in the equation

We get


Therefore, our final set of solutions are
