Two sides of an equilateral triangle measure (y+ 10) units and (y - 2) units. if the perimeter of the triangle is 21 units, what is the value of y

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.