Ответ:\(84 : 4 = 21\)\(20 \cdot 3 = 60\)\(12 \cdot 5 = 60\)\(60 : 15 = 4\)\(750 - 40 = 710\)\(600 + 50 = 650\)\(100 - 2 = 98\)\(900 + 7 = 907\)