Question

Which of the following choices is the common difference between the terms of this arithmetic sequence?

3x + 7y, 8x + 4y, 13x + y, 18x - 2y, 23x - 5y, ...

A. 3x - 7y
B. 5x - 3y
C. 5x + 3y
D. -5x - 3y
E. 3x + 7y

Answer 1

d = 5x - 3y <=ANSWER 

8x + 4y - (3x + 7y) = 5x - 3y 
13x + y - (8x + 4y) = 5x - 3y 
18x - 2y - (13x + y) = 5x - 3y