Question

2+2×3+2×3²+2×3³+...+2×3⁷⁵
DAU COROANĂ SI STELE!!!​

Answer 1

Explicație pas cu pas:

$2 + 2 \cdot 3 + 2 \cdot {3}^{2} + 2 \cdot {3}^{3} + ... + 2 \cdot {3}^{75} = \\ = 2 \cdot (1 + {3}^{1} + {3}^{2} + {3}^{3} + ... + {3}^{75})\\ = 2 \cdot \frac{1 \cdot \Big({3}^{76} - 1\Big)}{3 - 1} = 2 \cdot \frac{{3}^{76} - 1}{2} = \bf {3}^{76} - 1$