A set has closure under an operation if performance of that operation on members of the set always produces a member of the same set; in this case we also say that the set is closed under the operation.
A closure property is a certain rule that holds <u>if it is true for all elements of a set under the given operation</u> and a closure property does not hold <u>if there is at least one pair of elements that do not follow the closure property under the given operation.</u>
Therefore, Emma is correct, because you can find a counterexample (7:2=3.5) that gives you a non-integer answer.
Answer: correct option is B
Answer: 
Step-by-step explanation:
66.5cm
Split the shape into a square and triangle and find the area separately
Square: 8*7=57
Triangle: 7*3/2 = 10.5
=66.5
