In an A.P., if S5 + S7 = 167 and S10 = 235, then find the A.P.
Answers
Answered by
2
First of all you will find the first term
Tn=a(n-1)d
and put the and use the formula of Sn =n/2[2a +(n -1 )d]
Tn=a(n-1)d
and put the and use the formula of Sn =n/2[2a +(n -1 )d]
Answered by
15
Answer:
S5+S7=5/2(2a+4d) +7/2(2a+6d)=167
=5a+10d+7a+21d=167
=12a+31d=167 [let this be eqn 1]
similarly,
from S10=235, we get 2a+9d=47 {let this be equation 2}
by solving eqn 1 and 2, we get a=1 and d=5
therefore the ap is 1,6,11........
Step-by-step explanation:
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