Question

sum of the first 9 terms of an arithmetic sequence is 261.sum of next 6 terms is 444.(1)find the common difference and first term?​

Answer 1

Answer:

HERE IS YOUR ANSWER...

Step-by-step explanation:

Let first term = a, common difference = b,

t1 = a , t9 = a + (9–1)*b = a + 8b , according to condition , a+a+8b = 24…..(1),

When we find the sum of first nine terms , we have first term is a , and last term l = a+8b, number of total terms , n= 9,

S = n/2*{a+l} = 9/2*{a +a+8b}. Now putting a+a+8b = 24 from equation (1)

S = (9/2)*24 =108

Read more on Brainly.in - https://brainly.in/question/18800451#readmore

Answer 2

Answer:

n/2(2a+(n-1)d)=sn =261

sn =444.9/2(2a+8d)=261.15/2(2a+14d)=705.58=2a+8d.94=2a+14d-6a=-36

then a=6 1212+8d=261 d=321

I hope this helps you

pls mark as brainliest and follow me pls!!!!!!!