iv) In an A.P. 19th term is 52 and 38th term is 128, find sum of first 56 terms.
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3
Answer:
d=4
a=-20
sum of 56 terms = 5040
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Answer:
a19=52
a38=128
S56= 56
a+18d=52
a+37d=128
by eliminating method
d=4
a= -20
By Formula
Sn = n/2[2a+[n-1]d]
u can solve......
HOPE THIS WILL HELP U
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