Ineed to know the answer and how to get it

Volume of cylinder with a radius of 8cm and height of 25 cm

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b