Can you give more specific information about this question
90 ones would make 9 tens. It makes 9 tens because theres a 0 after 90. The 0 represents another place value. You can write this as 9 groups of ten
Warren spends 117 minutes ( 1 hour, 57 minutes) exercising over the weekend.
Try this:
1. sum of numbers is x+y=67, the difference between them is x-y=11
2. it is possible to make up and resolve the system: