The ratio of blue marbles to red marbles is 5:3. If you have 9 red marbles, how many blue marbles do you have?

15

Step-by-step explanation:

9/3=3, 3x5=15

The coordinates of A is (-1, 2)

You just first move over to the left on the X axis making your x coordinate a negative. So when you you get to -1 you go up to where A is, which is at positive 2. Your y coordinate is positive because you're moving up on the Y axis and not down.