Answer:
When we do not have anything cut of the rectangle, the area is:
8in*5in = 40in^2.
Now, when we cut squares of length x in the corners, the measures of the base will be:
8in - 2*x
5in - 2*x
We subtract two times x in each case because we cut the squares in the four corners. (below you can see a drawing of this situation, where the doted rectangle is the area that we want to calculate)
Then the area as a function of x is:
A = (8in - 2*x)(5in - 2*x) = 40in^2 + 4*x^2 - 26*x
