OI need help with geometry

Yesterday, george drank 1 small bottle and 2 large bottles, for a total of 1,372 grams. the day before , he drank 1 small bottle and 1 large bottle, for the total of 858 grams. how many grams does each bottle hold?

Determine if the equation defines y as a function of x: 2xy = 1. yes o no

What is the domain of the step function f(x)=[2x]-1?