Solution:
Let a – d , a, a + d are the first three terms.
Sum of three terms = 6
a – d + a + a + d = 6
3a = 6
a = 6/3
a = 2
Product of three terms = -120
(a – d) a (a + d) = -120
a (a²-d²) = - 120
2 (2² –d²) = -120
2(4 - d²) = -120
(4 - d²) = -120/2
(4 - d²) = -60
- d² = -60 – 4
- d² = -64
d = √64
d = ± 8
a = 2 d = 8 a = 2 d = -8
-6 , 2 , 10 10,2,-6
Therefore the three terms are -6 , 2 , 10 or 10,2,-6