What is “8 - 4(-x + 5)” equivalent too?

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

Mis the midpoint of rq if rm equals 2x + 5 and mq equals 4x - 9 what is the length of rq

State one method by which you can recognize a perfect square trinomial.