Which of the following represents 0.63 as a fraction in simplest form?

Which of these equations, when solved, gives a different value of x than the other three? a9.1 = -0.2x + 10 b10 = 9.1 + 0.2x c10 – 0.2x = 9.1 d9.1 – 10 = 0.2x

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

Can someone me out here and the tell me the greatest common factor