not sure why I got this wrong

[bailey]

2b
2b-a the letters are actually exponents. I came out with the answer being just "a", because everything cancels out and you are left with a -a on the bottom of the fraction, so I flipped it to

the top to get rid of the negative exponent. It was marked wrong on my test, and I am not sure why. Please help.

 

[srmichael]

2b
2b-a the letters are actually exponents. I came out with the answer being just "a", because everything cancels out and you are left with a -a on the bottom of the fraction, so I flipped it to

the top to get rid of the negative exponent. It was marked wrong on my test, and I am not sure why. Please help.

\(\displaystyle \displaystyle\frac{a^m}{a^n}=a^{m-n}\)

Using this little diddy, \(\displaystyle \displaystyle\frac{2^b}{2^{b-a}}=2^{b-(b-a)}=2^a\)

You can't just "cancel out" everything leaving a "-a". That makes no sense. Do you see why?

 

[bailey]

Thanks!!

\(\displaystyle \displaystyle\frac{a^m}{a^n}=a^{m-n}\)

Using this little diddy, \(\displaystyle \displaystyle\frac{2^b}{2^{b-a}}=2^{b-(b-a)}=2^a\)

You can't just "cancel out" everything leaving a "-a". That makes no sense. Do you see why?

Yes I think I understand, thank you so much!!