Help please i have been stuck in this question for an hour

You have 3 boxes, one "strawberries"; one "mentos" and one "mixed".but you know that all the labels are in incorrect order .how do you know witch is witch?

Marla bought a book for $12.95, a binder for $3.49, and a backpack for $44.99. the sales tax rate is 6%. find the amount of tax and the total she paid for these items

Asystem of equations has 1 solution. if 4x-y=5 is one of the equations , which could be the other equation ?