Luis left a 15% tip on a $30.00 food bill. how much did he leave for the tip?

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

The actual length of side t is 0.045cm. use the scale drawing to find the actual side length of w

The pyraminx is a rubik's cube-type toy in the shape of a tetrahedron. the pyraminx shown below has edges 15\,\text{cm}15cm long and vertical height h=12.2\,\text{cm}h=12.2cm. the triangle drawn with dashed lines is a right triangle. what is the distance rr? round your answer to the nearest tenth.