Cпростити вираз 70*(71^9+71^8+...+71^2+71)+71

Question

Cпростити вираз 70*(71^9+71^8+...+71^2+71)+71

Answer 1

Aⁿ - 1 = (a-1)(aⁿ⁻¹+aⁿ⁻²+.....+1)
70*(71⁹+71⁸+...+71) + 71 = 71*(71 - 1)(71⁸+71⁷+....+1) + 71 = 71*(71⁹-1)+71 = 71¹⁰ - 71 + 71 = 71¹⁰