facotr -9
add factors
-1+9=8
correct
Because the ratio for both candles is 20/60 or 1/3 then take the number of ounces the candle has and divide by 1/3. In expression: 9 / 1/3 => 9 * 3 = 18
The greatest common factor is 2
This is because we start by taking the largest factor that goes into both coefficients. Since the first coefficient is 2, we have to try 2 and 1. Since 2 is larger and goes into 36 evenly, we use that.
Then we use the smallest number of each variable. There are 4 r's in both equations. So, that is the number that we take. There are 2 s's in the first term, so we take that number.
Since an hour has 60 minutes you will take away 5 from 25 and put the 5 on 55 to get 9:00 then you add the rest to get 9:20.
Hope this helps. :)