(1)72÷3=24,24×36综合算式为:72÷3×36=864.(2)49-28=21,31×21综合算式为:31×(49-28)=651.(3)76-28=48,198÷9=22,48×22综合算式为:(76-28)×(198÷9)=1056.故答案为:72÷3×36,864; 3...