1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 2 10 2

Ans: -55

1^2-2^2+3^2-4^2+...+n^2= - n*(n+1)/2 (If n is Even)
1^2-2^2+3^2-4^2+...+n^2= n*(n+1)/2 (If n is Odd)
Here n=10
So Sum= - 10*11 /2= -55
8 years agoHelpfull: Yes(5) No(0)
(1^2+3^2+5^2+7^2+9^2)-(2^2+4^2+6^6+8^6+10^2)=-55
9 years agoHelpfull: Yes(4) No(1)
Sum of square of even terms=2n(n+1)(2n+1)/3 and sum of square of odd terms =n(2n+1)(2n-1)/3
here number of both odd and even terms is 5
thus putting 5 in place of n ,the result is -55
9 years agoHelpfull: Yes(3) No(0)
1^2 = 1*1=2 and 2^2 = 2*2=4 and 3^2=3*3

so that way we get

1 - 4 + 9 - 16 + 25 - 36 + 49 - 64 + 81 - 100 = - 55
9 years agoHelpfull: Yes(2) No(0)
3^2-2^2=(3+2)(3-2)=5
similarly for 5^2-4^2, 7^2-6^2 etc
the final ans would be after solving
1+5+9+13+17+100=145
9 years agoHelpfull: Yes(0) No(5)
ANSWER is -48
9 years agoHelpfull: Yes(0) No(9)
a2-b2= (a+b)(a-b)

use this,, 1(2)-2(2)=(3)(-1)=-3
3(2)-4(2)=(7)(-1)=-7
9 years agoHelpfull: Yes(0) No(1)

1^2 – 2^2 + 3^2 – 4^2 + 5^2 – 6^2 + 7^2 – 8^2 + 9^2 – 10^2=?

pls provide answer