Christine has a bookcase with 21 books. There are 7 shelves in the bookcase. Each shelf has the same number of books. How many books does each shelf have?.​

The map shows the location of the airport and a warehouse in a city. though not displayed on the map, there is also a factory 112 miles due north of the warehouse. a truck traveled from the warehouse to the airport and then to the factory. what is the total number of miles the truck traveled?

In δabc, m∠acb = 90°, cd ⊥ ab and m∠acd = 45°. find: a find cd, if bc = 3 in

Anumber is equal to twice a smaller number plus 3. the same number is equal to twuce the sum of the smaller number and 1. how many solutions are possible for this situation