AP calculus
posted by Watermelon .
The consecutive terms of an arithmetic progression are 5x, 8, 2x. Find the common difference of the progression.

The common difference of an A.P. is constant, therefore, we can take the difference of consecutive terms and equate the values to determine x:
2x8 = 8  (5x) =>
2x  x = 85+8 =>
x = 11
or
common difference
=2x8
= 14