Question

metoda de rezolvare: 1²+2²+3²+.....2019²​

Answer 1

Explicație pas cu pas:

$\boxed {{1}^{2} + {2}^{2} + {3}^{2} + ... + {n}^{2} = \frac{n(n + 1)(2n + 1)}{6}}$

${1}^{2} + {2}^{2} + {3}^{2} + ... + {2019}^{2} = \dfrac{2019 \cdot (2019 + 1) \cdot (2 \cdot 2019 + 1)}{6} = \dfrac{2019 \cdot 2020 \cdot 4039}{6} = 673 \cdot 1010 \cdot 4039$