A multiple of a number is the power of a number

What is the product? a-3/15a × 5/a-3

Pls what is the decimal equivalent of 5 over 9? select one: a. 0 point 5 bar over top of 5 b. 0 point 6 bar over top of 6 c. 0 point 8 bar over top of 8 d. 0 point 9 bar over top of 9

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.