A restaurant bill is 56.39.Estimate a 20% tip

The random variable x is the number of occurrences of an event over an interval of ten minutes. it can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. it is known that the mean number of occurrences in ten minutes is 5.3. the appropriate probability distribution for the random variable

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.

How do you solve a question like this?