Pls help st math rates.

You are measuring the dimensions of the floor in your bedroom because you are planning to buy new carpet. which unit of measure is the most appropriate to use in this situation?

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).