Question

solve 1^2+2^2+3^2+..........+15^2

Answer 1

n(n+1) (2n+1) /6

15(16) (31) /6

=1240

Answer 2

Heya❤

$1 {}^{2} + 2 {}^{2} + 3 {}^{2} + 4 {}^{2} + 5 {}^{2} + 6 {}^{2} + 7 {}^{2} + 8 {}^{2} + 9 {}^{2} + 10 {}^{2} \\ + 11 {}^{2} + 12 {}^{2} + 13 {}^{2} + 14 {}^{2} + 15 {}^{2} \\ \\ = 1240$

Hope it helps you

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