Question 14584
Let x = the first number and y = the second number.  You can write:

3x - y = 9  Three times the 1st number (3x) decreased by the 2nd number (-y) = 9
2x + y = 11 Two times the 1st number (2x) increased by the 2nd number (+y) = 11

There are the two equations you need.  Can you take it from here?