Question

Обчислити зручним способом 1)73×15-15×71; 2)441×16+559×16; 3)125×423+125×377

Answer 1

1) 73 * 15 - 15 * 71 = 15 * (73 - 71) = 15 * 2 = 30

2) 441 * 16 + 559 * 16 = (441 + 559) * 16 = 1000 * 16 = 16000

3) 125 * 423 + 125 * 377 = 125 * (423 + 377) = 125 * 800 = 100000