Great method, Anju!

And one more thought for you on this, Felix - on the GMAT you're never doing algebra in a vacuum...there's always either answer choices or a Data Sufficiency question stem and they'll often give you clues. For example, in this question:

If it's problem solving, it might well ask "which of the following is a possible value of t?"

(A) -24
(B) 14
(C) 4
(D) 24
(E) 28

And you could then think in terms of number properties (the digits of 672 add to a multiple of 3, so -24 or 24 are looking pretty good as first numbers to try factoring since you know that one of the two roots of this problem is a multiple of 3) or gaming the answer choices (since there's both a -24 and a +24, 24 is likely a factor...OR...672 is a pretty big number so it's most likely that 4 isn't a factor, but something in the 20s is).


Or, if it's a Data Sufficiency question, it might ask:

Is t > 25?

In which case you'd want to test numbers in that 22-30 range since you know that one of the factors will be close.


So keep an eye on the structure of the question around the quadratic and you'll often find clues that help you streamline which options you try, and again like Anju said if that middle term is small her method is fantastic.

Dear Felix,

Your approach is perfect in its own place, but GMAT models get scaled up over time, and as the complexity goes up you may need to adjust or even abandon techniques that have worked well before. In particular, you need to build-in a recognition function: Yes, I kind of know this problem, but my solution will take forever here, so what else do I see?

Kind Regards,

Misterholmes