Answer : 70
Step-by-step explanation: because 40 +30 and the biggest number in the chart is 7 just add a 0 and it becomes 70
45 of a number refers to 180, and 54 refers to 216. So 100 of a number is 400 and 1 of a number is 4. If 54x - 45x = 36, just plug in 4 and double check: 54(4) - 45(4) = 36 or 216 - 180 = 36, which is true.