What is the value of x? (Use only the digits 0 - 9 and the decimal point, if needed, to write the number.) x + 12.66 = 18

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.