Is 3x+y=12 linear or nonlinear

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?

15 oranges weigh 3.75 kilograms (kg). if each orange weighs approximately the same, approximately how much does each orange weigh?

The first term of a sequence is -12. the recursive formula for the sequence is an = an-1 + 9. what are the next 3 terms in the sequence? a) -3, -15, -27 b) -3, 6, 15 c) -3, -6, -3 d) -3, -6, 3