What is the gratest common factor of 36 and 18?

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

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

Which expression can be used to determine the slope of the line that passes through the points -6, three and one, -9