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

How do I go about solving for $x$ in this equation?

$$\displaystyle -x^{-\large\frac{3}{4}} + \frac{15^{\large\frac{1}{4}}}{15} = 0$$

share|cite|improve this question
I've edited for formatting --- please check to see that I got it right. – Gerry Myerson Feb 18 '13 at 23:40
You had it right @Gerry. Then it was edited after your edit using teeny-tiny fractional exponents. So I made them larger. – amWhy Feb 18 '13 at 23:48

Hint: $$-x^{-3/4} + \frac{15^{1/4}}{15} = 0 \iff -\frac {1}{x^{3/4}} + \frac{15^{1/4}}{15^{4/4}} = 0$$

$$\iff -\frac {1}{x^{3/4}} + \frac{1}{15^{3/4}} = 0$$

$$\iff \dfrac{x^{3/4}}{15^{3/4}} = 1 \iff \left(\frac{x}{15}\right)^{3/4} = 1$$

Can you take it from here?

share|cite|improve this answer
its 15! Thanks! – user62885 Feb 18 '13 at 23:43
Yes, your correct! You're welcome! – amWhy Feb 18 '13 at 23:45

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.