Question

in an AP the sum of first 10 terms is -150 and the sum of it's next 10 terms is -550. find the AP.​

Answer 1

Answer:

Here, given that...

The sum of first 10 terms of an A.P is 100...

i.e S10=100 and S10-- S20=300. We know that,

S =n/2[2a+(n–1)d]

i.e,, S20=20/2[2a+(20–1)d]

S20=10[2a+(19d)]=400 -------------{1}

Similarly.,

S10=10/2[2a+(10–1)d]

i.e,, S10=5[2a+(9d)]=100 ------------------{2}

By solving {1} and {2}, we have

Step-by-step explanation:

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