I think the answer is 15:7 Correct me if i'm wrong...
One expression you can write 9(3) + 7(4)= 55
You divide by 6 to each number then you get x by itself then x equals 10
The answer would be H. All you have to do for a problem like this in the future are to add the 3 different angles together and make sure they equal 180 degrees.
WEll FIRST IT WRONF THEN IT IS