Question

Sum of first 9 terms is 261 and next 6 terms is 444 .find common difference and first terms algebraic expressions

Answer 1

Answer:

given

sum of first nine terms is

A1+A2+A3+ --------------+ a9. = 261

A10+ A11+ -----------_----a15= 444

Step-by-step explanation:

then by the problem

9a + 36d = 269. ( 1 )

6a + 69d = 444. ( 2 )

let eq ( 1 ) × 6

and eq (2) × 9 =

54a + 216 d = 269× 6

54a + 621d = 444× 9

subract eq 1 from eq 2