Anontoxic furniture polish can be made by combining vinegar and olive oil. the amount of oil should be five times the amount of vinegar. how much of each ingredient is needed in order to make 39 oz of furniture polish?

It would contain 6.5 oz of vinegar and 32.5 oz of oil.

Let V be the amount of vinegar and L be the amount of oil.

Since the amount of oil is 5 times the amount of vinegar, L = 5V.  We know that together they form 39 oz; therefore
V + 5V = 39
6V = 39

Divide both sides by 6:
6V/6 = 39/6
V = 6.5

L = 5V = 5(6.5) = 32.5