In an Ap the sum of first 10 terms is -150 and sum of its next 10 terms is -550.find the A.P

In an Ap the sum of first 10 terms is -150 and sum of its next 10 term

1.	In an Ap the sum of first 10 terms is -150 and sum of its next 10 terms is -550.find the A.P
Answer» AP will be 3,-1,-5,-9 Sum of first ten terms = 10/2(a + (10-1)d) = 5(a+9d)=-150 .....1Sum of first twenty terms = 20/2(a + (20-1)d = 10(a + 19d) ....2Sum of first twenty - sum of first 10 = sum of next 10 terms=-550So -150-10a - 19d = -550= -10a -19d= 400Substitute value of a from a in the terms of d and find that A. P.