I'm struggling to solve the problems on the images and was wondering if I could get some help.

Abox of chocolates cost $7 which equation relates the number of boxes sold parentheses x parentheses and total cost of the boxes sold parentheses y parentheses

Renee hiked for 6 3 /4 miles. after resting, renee hiked back along the same route for 5 1 /4 miles. how many more miles does renee need to hike to return to the place where she started? represent your answer as a simplified mixed number, if necessary.

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.