Nathan went to the grocery store and bought bottles of soda and bottles of juice. each bottle of soda has 25 grams of sugar and each bottle of juice has 35 grams of sugar. nathan purchased 3 more bottles of juice than bottles of soda and they all collectively contain 405 grams of sugar. write a system of equations that could be used to determine the number of bottles of soda purchased and the number of bottles of juice purchased. define the variables that you use to write the system.