>>So, where's the rest of the solution? :))

There is a smile there! I think there were already 2-3 correct answers here, on this thread. I was just joking because the message I was repling to it was unfinished.

>As far as I remember:

A little too far... :)

>y = (X+3)*(X+24) =
>y = X^2 + 27X + 72

Correct.

>Y = (-27X +/- SQRT(27X^2-4*X^2*72))/(2*X^2)

Not correct.

>Is the old (-b +/- SQRT(b^2-4ac)/2a

This is the formula. You must know also what a, b and c means. This is the solution for the general second degree equation:

aX^2+bX+c=0

which can have none, 1 or 2 solutions, depending on a, b, c. (In fact, if we're looking for a complex solution, there is always at least one.)

Vlad