(28 : 100) *6 = 1.68 (tax)
28 + 1.68 = 29.68 (total cost)
You can make 4 triangles out of a 3x3 square.
Could you post a picture with the graphs in it? Kinda hard to answer your question without the answer choices :)
Well, you could subtract or add or multiply or divide for example 45 + x=50 you could subtract 50 from 45 and get 5 there are many ways you can find missing values.