X/12=-7 what's the answer? show work

Kelly is three years younger than her sister. the sum of their ages is 34 years. how old is kelly and how old is her sister?

Boris needs to buy plastic spoons. brand a has a box 42 spoons for $2.37. brand b has a box of 72 spoons for $3.57. find the unit price for each brand. then state which brand is the better buy based on the unit price. round your answer to the nearest cent.

The median for the given set of six ordered data values is 29.5 9 12 25 __ 41 48 what is the missing value?