The arithmetic property used to rewrite the numeric statement is:
A. Associative property of addition
The statement is:
( 6 + 3 ) + 21 − 8 = 6 + ( 3 + 21 ) − 8
In it, the order of the parenthesis is changed, which is the associative property of addition, which states that changing the grouping(order of parenthesis) of the terms does not change the sum.
Hence, the correct option is A.
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