We know that the 2nd term has a value of 8. Thus a + 6b = 8;What is more, we also know that the 5th term has a value of 44. We also know that the next element in the sequence increases by 4b when compared to the previous one. Hence the 5th element will be equal to a + 18b.Thus: a + 6b = 8 eq.1 a + 18b = 44 eq. 2Let's subtract the two equations - eq.2 -eq.1 we get 12 b = 44-8 = 36. Hence b = 3 and a = -10