(3+4root(15))/(4-3root(15))

please show me your work

Do you want the actual number or do you want the denominator rationalized to get the radical out?

You can do the former with a hand calculator, or tools available on the internet. To do the latter, multiply the numerator and denominator by 4 + 3root(15)

That will make the new denominator
16 - 9*15= -119
and the new numerator
(3+4root15)(4+3root15)
= 12 + 25root15 + 12*15
= 192 + 25 root 15
So the new value is
(-192-25 root15)/119
The value of that number is -2.427