Question

Considering the doubling plus one function: The output is 2 times the input, plus one. For example, if the input is 3 the out put is 7. Determine which of the following points are on the graph of the doubling plust one fuction:
(2,5), (2,8), (-1,1), (3,4), (-2,-3), (1.5,4), (0.5,1.5)