The formula to find the slope of a line is

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I'm not sure if my fraction looks right, so I'll add it in a separate attachment too.
52 - 37 = 15
67 - 52 = 15
82 - 67 = 15
The common difference for this arithmetic sequence is 15.
Answer: C.
You would use the distributive property to solve the equation to remove exponets then to get your final equation.