72 is dividable by 3. It is divisible by 3 because when you add 7 and 2, you get 9. According to the tests for divisibility, if the sum of the digits is divisible by 3, then the whole number is. 9 is divisible by 3, therefore 72 is as well.
Answer:
5/7
Step-by-step explanation:
4/3
(-)(-) = +
It was first done by William Jones in 1706