Quick math question

[platinumike]

studying for an economics test and my brain is like mush right now. I have
625=3125000p^-4 - 12,500,000p^-5
how would i solve this?

 

[Adn4n]

Graph it on your calculator and find the x-intercept.

 

[darkxshade]

42

 

[legoman666]

factor and then find the zeroes.

0.0002 = p^-4(1 - 4p^-1)

just graph it on a ti83 and find the intercepts.

 

[Adn4n]

But if you are not allowed to use a graphing calculator, factor out the X term, either in the form it is now of multiply by X^5 to eliminate the X's in the denominator. That means that one of your answers in 0. The other answer is whatever the other X term is equal to.