Help finding Perpendicular angles

Hi my sisters and brothers can tell me the answer because i don’t understand the question

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 is a correct first step in solving the inequality-4(3-5x)> -6x+9