Find the four arithmetic means between 12 and 13 6 1 3 8 6 2

Find the four arithmetic means between 12 and -13. 6, -1, -3, -8 6, 2, -3, -8 7, -1, -3, -8 7, 2, -3, -8

Solution

12, ___, ___, ___, ___,-13

here a=12

-13 = 12 + 5d

5d = -13-12

5d =-25

d =-5

so

the four terms are a+d,a+2d,a+3d, a+4d

the terms are 7,2,-3,-8

option D). is the answer