Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Really hard problem!!

$$ \begin{align} xy&=-2 \\ xy^{a-1} &=-512 \\ x(y^a-1 ) &= 341y-341 \end{align} $$

share|cite|improve this question
Plugging the 1st and 2nd equations into the 3rd, we get a quadratic equation for y. – pharmine Nov 9 '11 at 9:42
Did you want the third equation to be $x(y^a-1)=-341y-341$? The solution is much nicer then. – David Mitra Nov 9 '11 at 10:05

From the first two (divide them) you get $y^{a-2}=256$.

So the third becomes $xy\cdot y \cdot 256 -x=341y-341$.

$-512 y-x=341y-341$. Plug $x=-2/y$ in this last equation you get a quadratic equation.

It is not really that hard problem. You just have to play a bit with it.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.