What is the answer to y-16 factorised

Kayla made observations about the sellin price of a new brand of coffee that sold in the three different sized bags she recorded those observations in the following table 6 is $2.10 8 is $2.80 and 16 is to $5.60 use the relationship to predict the cost of a 20oz bag of coffee.

What’s the answer? and how do i solve it ?

Y=x+2 4x+3y= -36 system of equation