Question

Please answer this. It is from Arithmetic Progressions for grade 10​

Answer 1

Answer:

Let the first term of two AP's be a and A and common difference be d and D.

Now,

We know

Sn = n/2{2a+n-1}d

Therefore,

n/2{2a + (n-1)d} : n/2{2A + (n-1)D} =

7n+1 : 4n + 27

2a + (n-1)d: 2A + (n-1)D= 7n+1 : 4n+27

Replacing n by 17 (2×9-1)

Therefore

2a + 16 d : 2A + 16D = 120:95

a + 8d : A + 8D = 24 : 19

Therefore

Sum of their ninth term is 24 : 19 ..

I think you will appreciate me

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ankyou

Step-by-step explanation: