A bag contains white marbles and blue marbles, 57 in total. The number of white marbles is 9 more than 2 times the number of blue marbles. How many white marbles are there?

Uneed to add them up 27+18+23=68

This law is sometimes called the grouping property. as you can see, regardless of how the numbers are grouped, the answer is still 13. the associative law of multiplication is similar to the same law for addition. it says that no matter how you group numbers you are multiplying together, you will get the same answer.