What one do you need help with?
7X-4=6X-4-X
7X-6X+X=0
2X=0
X=0
10 15 20 since i am pretty sure the rest are a triple(definitely 3 4 5 and 7 24 25 is a triple0
The list of possible outcomes in the question is totally incomprehensible. But from our vast experience with questions like this and dice in general, we know there are 36 of them.
Now, here are all the ways to roll a total of 9:
3, 6
6, 3
4, 5
5, 4
Four of the 36 possible rolls result in a 9.
So the probability (with honest dice) is 4/36 = 1/9 = 11.1% .