Your original problem is x^3+x^2+x+1=0. To begin the problem you must first look at the signs you currently have.
After you do that you must then take a real root and plug it into your P(x). In this case you will have P(-x) and the begin on with your problem.
After ypu have plugged this in then you will get the above answer. It differs from the original
From the original problem all of the positive signs, except for the last one, turned into negative signs when you replaced your P(x) with P(-x).
That means you have 3 sign changes instead of 1 like the person originally doing the problem stated.
A gardener is designing a new garden in the shape of a trapezoid. She wants the shorter base to be twice the height and the longer base to be 4 feet longer than the shorter base. If she has enough topsoil to create a 60ft^2 garden, what dimensions should she use for the garden?
Since she has enough topsoil to cover 60ft^2 garden then you can plug the numbers into the above formula.
Once you have plugged in your numbers from your two bases and height you must the reduce your problem.
Once you have reduced this far you must combine the two like terms.
After you have reduced it completely down then you must divide it all.
Once you have divided the problem down to a simpler form then you use the positive number to be plugged back in, since it cannot be negative to find height.