What is ten times the sum of half a number and 6 is 8

In the surface area formula for cylinders which expressionrepresents the lateral area

Can you me find the missing length. i attached an image.

Match the vocabulary to the proper definition. in probability, two events in which 1. conditional probability the outcome of one event is independent of the outcome of a second event. 2. dependent events in probability, two events in which the outcome of one event is dependent on the outcome of a second event. the probability of an event in which the outcome of the event is conditional on the outcome of one or more different events. 3. independent events