What is the midpoint between (-6, 3) and (4, 9)?

  (-1, 6)

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Explanation:

The x coordinates of the two points are -6 and 4. They add to -6+4 = -2. Cut this in half to get -2/2 = -1.

The y coordinates of the two points are 3 and 9. They add to 3+9 = 12. Cut this in half to get 12/2 = 6.

The midpoint formula is

In short, you add the corresponding coordinates and then divide by 2.

n = 20

Step-by-step Explanation:
When dealing with ratios, there is always most likely a second number given to you. This number is going to be 1.
When looking for n, you have to look for all of the numbers, in this case there is only two.
1 is the hour, so now you just need the 20 minutes.
If the ratio is 1:n, this means that n would have to equal 20.
1:20