2x-3y=8 solve for y i don't understand this at all can someone ? ?

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?

An art teacher made a copy of a small painting. to make the painting easier to see the teacher enlarged the area of the painting by 49%. let y respresent the area of the original painting. the expression below is one way to resperesnt the area of the new painting. find two equivalent expressions that would give the area of the new painting y+0.49y

4. jake needs to score in the top 10% in order to earn a physical fitness certificate. the class mean is 78 and the standard deviation is 5.5. what raw score does he need? z value for top 10% =1.282 how do i get the z value? what is the equation for this? raw score =mean+z*sd = 78+1.282*5.5 = 85.051