Find the sum first 15 terms of the
a.P 8,7 1/4,6 1/2,5 3/4
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Answer:
56.25
Step-by-step explanation:
A.P : 8,7 1/4,6 1/2,5 3/4 , ... = a , a+d , a+ 2d , ....
a+d = 7 1/4 , a = 8 , d = -3/ 4
U15 = a + 14d = 8 - 14(3/4) = ( 32 -42)/4 = -10/4
sum = 15/2(8-10/4) = 15/2(30/4) 450/8 = 56.25
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