Factoring out Exponents

[dddannie6]

Hi.

I have no clue how to factor out exponents with the same base but that need to be subtracted or added. A example of what I mean is let say 3^4 - 3^6. I cannot subtract the exponents because you can only do this when you divide numbers with exponents, so then what do I do?

Thanks,
Dannialles D

[gbd97]

Hi we can take common the smallest one....like i did it below...
3^4-3^6
=3^4(1-3^2)
=3^4(1-9)
=-8*3^4
hope, it helps.

[tommywallach]

That's absolutely right. And just to be clear, you always factor out the greatest common factor of your terms. 3^4 is the biggest thing that both terms have in common, so that's what you pull out!

-t