Answer:
Associative propertry of addition.
Step-by-step explanation:
The associative property of addition states that:
It states that we can add numbers regardless of the groups. The sum does not change irrespective of how the addends are grouped.
We are given the expression:
It can be written as:
It can also be written as:
Whatever maybe the arrangement of r, h and t, their sum will always be equal. We can regroup them in many ways but the sum remains the same.