Обчислити зручним способом 74.7•2/21+(-105.3)•2 3/7-(-105.3)•2/21-2 3/7•74.7
74,7(2/21-2 3/7) + 105, 3(2/21 - 2 3/7)= (2/21-2 3/7)(74,7+105,3)= - 2 1/3*180=-7*180/3=-7*60=-420