ccax is a math Guru and his Qs are definitely harder than GMAT Qs
ccax is there an easier way to solve this Q?
First of all giddi77, thanks for the flowers
I wish I could exchange the compliment into a decent GMAT score...
I don't think my questions are always harder than those of GMAT,
but I tried a few times to create a question that required to think
a bit different.
It's certainly true that you won't NEED 4th degree polynomials.
Because of that, I chose integers for the roots, so that the question
won't be too hard.
If you consider that a 4th degree polynomial can be represented as
(x-a)(x-b)(x-c)(x-d), where a, b, c and d are the roots, and you
expand this, then the only number independent from x is a*b*c*d,
which in our case was +8, representing the product of all roots of
There aren't that many possibilites if all roots have to be integers,
so just try a few values. You won't need polynomial division in the
In calculating the roots of a polynomial, there are general formulas
for a polynomial up to 4th degree (that are exponentially growing
more complicate for 3rd and especially 4th degree). For polynomials
of a degree bigger than 4, there are only formulas for special cases.
As for the GMAT, you only need to bear in mind the formula for
x^2 + b x + c = 0.