(36+14)÷2 = 15×6-40= 81÷9÷3=90-(60÷5)= 36÷3-8= 7×8×9=25×4×5= 20-72÷6= 90÷3÷3=30×60÷5=答案25 50 3 78 4 504 500 8 10 36