The person that factored the polynomial did one thing wrong -- they used minus signs when they should've used plus signs. We can figure this out because of the values of the quantities in the original trinomial. Since all of them are positive, we know that either there are two plus signs or that there is a minus and a plus sign with the value to the right of the plus sign being greater than the value to the right of the minus sign. But, that wouldn't work here, so the only thing wrong with this answer is that the plus signs should be minus signs.
