Question

Which mathematical property is demonstrated 40•(25•74) = (40•25)•74

Answer 1

The mathematical property that allows 40 * (25 * 74) = (40 * 25) * 74 would be the Associative Property of Addition and Multiplication. This property means that no matter how the values of an expression are grouped together (or "associating" with each other), the end result will be the same, as long as the symbols are all either multiplication or addition symbols.
Hope that helped =)