How does -48/4 = -12 i need a step-by-step explanation

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.

Typically a point in a three dimensional cartesian coordinate system is represented by which of the following answers in the picture !

Check image and write the letter of the answer