I have two math questions I need answers to. 

1. Directions. Expand

  log (x^3 / 10000)

2. Directions: Write as a single logarithm

 5lnx - 8lny

Use these equations for 'log' or 'ln':

   log( x / y)  =  log x  -  log y
   log( x^y )   =  y log x

Also, assuming that 'log' means 'log to the base 10':

   log 10 = 1

1. log (x^3 / 10000)
   = log x^3 - log 10^4
   = 3log x - 4

2. 5 ln x - 8 ln y
   = ln x^5 - ln y^8
   = ln (x^5 / y^8)