Question 211881
Let x = the number 

Now break the sentence into parts and translate the words into an algebraic expression:

a) If 3 is added to the number:  x + 3
b) ...and the sum is tripled.. 
   "The sum" is "x + 3" so: 3(x+3)
c) ...the result is 27 more than the number.
   27 more than the number is x + 27

d) Put it all together:
   3(x + 3) = x + 27

Solve for x:

1) Distribute the left side of the equation:
   3x + 9 = x + 27
2) Subtract x from each side of the equation:
2x + 9 = 27
3) Subtract 9 from each side of the equation:
2x = 18
4) Solve for x:
x = 9

Check: 

1) x = 9
2) 3(x + 3) = x + 27
3) 3 ([9] + 3) = [9] + 27
4) 3(12) = 9 + 27
5) 36 = 36 
The answer is correct