10/3=? /9 and how do you get the answer

How do you use the elimination method for this question? explain, because i really want to understand!

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

If f(x) = -5x + 1 and g(x) = x3, what is (gºf)(0)? enter the correct answer