Trinity's science instructor entered the 7th students in a STEM competition. There was an enrollment fee of $50 and an additional fee of $12 for each packet of 10 tests. The total cost was $170. How many tests were purchased? Which of the following equations best models the situation?
Question 1 options:

12x + 50 = 170

50x + 12 = 170

12x - 50 = 170

50x - 12 = 170

Is there a direction u in which the rate of change of f(x,y)equals=x squared minus 3 xy plus 4 y squaredx2−3xy+4y2 at p(1,2) equals 14? give reasons for your answer. choose the correct answer below. a. no. the given rate of change is smaller than the minimum rate of change. b. no. the given rate of change is larger than the maximum rate of change. c. yes. the given rate of change is larger than the minimum rate of change and smaller than the maximum rate of change.