sorry, forgot to show my steps so far:
for the first qu:
I have it up to: 1/(4x^4)(-27x^12)
I don't understand how they got a 4 over 27x^16? I would think it would be a 1 over 27x^16.
For the second question:
I have 5sqrt(3a^4) = 48
and then I'm sorta stuck... could it be: 5*4=20, so (a^20)/3 = 16?