B. Between 20 and 25 minuets
Brooke's speed is decreasing between 20 and 25 minutes. According to the graph Brooke's speed is decreasing during that time period.
The solution to a system of equations is the point that the 2 lines of the graph cross each other.
x = 1 and Y =4
Solution is (1,4)
Answer is C.
<span>This is a very nice counting question.
Suggestion / Hint: Count how many ways he can get from (0,0) to (5,7) by going through the point (2,3). Then subtract that from ALL POSSIBLE ways he can get from (0,0) to (5,7).
Hint for the hint: How many ways he can get from (0,0) to (5,7) by going through the point (2,3)? Well, that's the SUM of how many ways he can get from (0,0) to (2,3) and how many ways he get get from (2,3) to (5,7).
Hope this helps! :)</span>
I think (0,0) is the only one that starts at 0 for both x and y and stay the same if the add the 3 to x and 6 to y.