Brainlest- Please please help me thank you so much in advance

Which of the following system of equation is not equal to the system of equations is not equal to the system of equations shown below

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

In the diagram, ab is tangent to c, ab = 4 inches, and ad = 2 inches. find the radius of the circle.