Jake required to find out the perimeter of an equilateral triangle whose sides measure x + 4 cm each. Jake realized that he could multiply 3 (x + 4) = 3x + 12 to find out the total perimeter in terms of x. Which property did he use to multiply?

In the statement, the order of the numbers does not change; therefore, the grouping of the numbers in parentheses does. Each side, if simpli?ed, results in an answer of 300, even by both sides look different. Changing the grouping in a problem such as this is an instance of the associative property of multiplication.