Question

Вычислите:
а)47*42+42*153;
б)57*81-71*57;
в)61*45+55*61;
г)39*138-137*39.

Answer 1

а) 47 * 42 + 42 * 153 = 42 * (47 + 153) = 42 * 200 = 8 400

б) 57 * 81 - 71 * 57 = 57 * (81 - 71) = 57 * 10 = 570

в) 61 * 45 + 55 * 61 = 61 * (45 + 55) = 61 * 100 = 6 100

г) 39 * 138 - 137 * 39 = 39 * (138 - 137) = 39 * 1 = 39