Question

if for an AP a5+a25=56, then a15 is?
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Answer 1

Answer:

28

Step-by-step explanation:

We know that a(n) = a +(n-1) d in arithmetic progression

here, a+4d+a+24d = 56

2a+28d= 56; 2a=56-28d

So a = 28-14d...(1)

Now, a(15) = a + 14d

a(15) = (28-14d) + 14d [Substitute a(15) with ...(1)]

a(15) = 28

Hope it helps...