for an A.P, t3=17, t7=37. Find S16 .
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Step-by-step explanation:
t3 = a+(n-1)d
17 = a + 2d...,......(1)
t7 = a+(n-1)d
37 = a+ 6d.............(2)
subtract (1) from (2)
a+6d = 37
a+2d = 17
___________
4d = 20
d = 5
from (1)
17 = a + 2d
17 = a + 10
a = 7
S16 = n/2 (2a+(n-1)d)
= 16/2 (14 + 15×5)
= 16/2 ( 89)
= 89×8
= 712
hope it helps you buddy
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