Question

find the sum of 1²+2²+3²+......+192
$1 { }^{2} + 2 {}^{2} + 3 {}^{2} + ..... + 192$
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Answer 1

Step-by-step explanation:

We have,

${1}^{2} + { 2 }^{2} + {3}^{2} + ... + 192$

$= {1}^{2} + {2}^{2} + {3}^{2} + ... + 169 + 23$

$= {1}^{2} + {2}^{2} + {3}^{2} + ... + {13}^{2} + 23$

$= \frac{13(13 + 1)(2 \times 13 + 1)}{6} + 23$

$= \frac{13 \times 14 \times 27}{6} + 23$

$= 13 \times 63 + 23$

$=842$

Answer 2

Step-by-step explanation:

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