Question

вычислите наиболее рациональным способом 154³-123³/31+154*123​

Answer 1

Ответ:

$\frac{ {154}^{3} - {123}^{3} }{31} + 154 \times 123 = \\ \frac{(154 - 123)( {154}^{2} + 154 \times 123 + {123}^{2} ) }{31} + 154 \times 123 \\ = \frac{31( {154}^{2} + 154 \times 123 + {123}^{2}) }{31} + 154 \times 123 = \\ {154}^{2} + 2 \times 154 \times 123 + {123}^{2} = \\ {(154 + 123)}^{2} = {277}^{2} = 76729$