Question 749505
Let x represent the third number.  Then the first number is x-9 and the second number is 3x.

Now, the sum of the numbers is 66, so set up an equation:

{{{(x-9)+3x+x=66}}}

Combine like terms:

{{{5x-9=66}}}

Add 9 to both sides:

{{{5x=75}}}

Divide both sides by 5:

{{{x=15}}}

Thus, the third number is 15.  The second was 3x, so 3*15=45.  The second number is 45.  The first number was x-9, so 15-9=6.  The first number is 6.  The numbers are 6, 45, and 15.