If you would graph the triangle, one of the legs would be 8 and another would be 5 and the area of a triangle is bxh/2 so the equation is 8x5/2=20un². Hope this helped! :)
Y= 10 + 1.25x This is the answer because 10 is the initial fee (you start with it) and 1.25 is added for each minute, with each minute being the variable
