The list of numbers – 10,

(b) The given numbers are -10,-6,-2, 2…………………..

Here, a., = -10, a2 = -6, a3 = -2 and a4 = 2………

Since, $\quad a_{2}-a_{1}=-6-(-10)$

$=-6+10=4$

$a_{3}-a_{2}=-2-(-6)$

$=-2+6=4$

$a_{4}-a_{3}=2-(-2)$

$=2+2=4$

Each successive term of given list has same difference i.e., 4.

So, the given list forms an AP with common difference, d=4.