Division can be used. For example
50/16=3.125gallons
or you could use multiplication
50*1/16=3.125gallons
Answer:

Step-by-step explanation:
First, expand to make it easier
y=x(x^2+5)(x^2+5)
y=x(x^4+10x^2+25)
y=x^5+10x^3+25x
differentiation
y'=5x^4+30x^2+25 is the derivitive