Determine whether quantities vary directly or inversely and find the constant of variation. an employee earns $175 for 15 hours work. assuming he is paid by the hour, how much will this employee earn in 18 hours?

The perimeter of △cde is 55 cm. a rhombus dmfn is inscribed in this triangle so that vertices m, f, and n lie on the sides cd , ce , and de respectively. find cd and de if cf=8 cm and ef=12 cm. the answer is not cd=20 and de=15. i have tried that one, it does not work.