Question

find the sum of 10+(-10)+10(-10)+.....if the number of terms is 121.​

Answer 1

Step-by-step explanation:

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

=121/2(2×10+(121-1)(-20))

=121/2(20+(120(-20))

=121/2(20-240)

=121/2(-220)

=121(-110)

=13310

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Answer 2

Answer:

0 is the ans

because + &- =-

so the +10 is cut with -10 both time