It opens upward and the vertex is (2,-6) here are some plotted points: (0,6),(1,-3),(2,-6),(3,-3),(4,6). Hope that helps. I hate graphing but if you do it enough times you'll get the hang of it!
The answer is 9/5
You do 9x1/5 so 9x1 is 9. That’s your numerator and 5x1 is 5 and that’s your denominator
If it is a ratio of 3:5 you are dividing 480 into 8 parts (3+5).
So divide 480 by 8: 480/8 = 60
Then the ratio is (3x60):(5x60) or 180:300
To check it is correct, add up the two parts to see that they come to 480:
180+300 = 480. All good.
Hope this helps