The answer is 3
Multiply 6 by 3 to get the total amount of money for the books then minus the answer 18 which you get from 6 x 3 = 18
Then minus 18 from 21 to get $3
21 - 18 = 3
I'm sorry but it's bugging me that you aid 'one cases', you can't have the plural of something that is strictly singular.
Now: for your answer.
72*35=2520
94*23=2162
2520+2162=4682
The total wight is 4682 pounds.
Hope this helps
6.270,6.270, 6.026,6.26, 6.3,
