rewrite 27 as 3^3and 9 as 3^2
so 3^3=3^2(x-5)
the bases are now the same so you can set the exponents equal to each other and solve
3=2(x-5)
3=2x-10
13=2x
x=13/2
Thank you very much. I understand it now, gotta make sure the bases are the same.
What if it wasn't as clear as to what the base was?
Something like 8^X=15. Would you have to first find a common base between 8 and 15?