The function and the first value stated for x are confusing.
Doing some research, I found that the problem is to evaluate the function

for x = - 1 and x 2.
The solution is:
1) For x = - 1

2) For x = 2
Unfortunately, this item does not come with any figure to illustrate the lengths of the rectangle. However, it may be noted that by connecting two opposite vertices of a rectangle by a diagonal, we form a right triangle. We may then use the Pythagorean theorem to solve for the answer.
a² + b² = c²
c in this equation is the length of the diagonal, a and b are the lengths of the sides.
She can make two cakes and 3 trays of cookies