Question

1+2+3+4+5+6......+11=?​

Answer 1

1-2+3+4+5+6+7+8+9+10+11

Answer=66

Answer 2

Answer:

a=1

d=1

n=11

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

Putting on the values.

we get 66 as the answer

Step-by-step explanation:

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