In this case, we are going to formulate an equation from the given statement. First we are told that 2 is added to a number that we are going to call x, then we can write:
x + 2
Then, we are told that this sum is tripled, that is we multiply the above expression by 3, then we get:
3(x + 2) = 3x + 6
And the above expression equals the number "x" plus 18, then we get:
3x + 6 = x + 18
From this expression, we can solve for x to get:
3x + 6 = x + 18
3x - x + 6 = x - x + 18
2x + 6 = 18
2x + 6 - 6 = 18 - 6
2x + 0 = 12
2x = 12
2x/2 = 12/2
x = 6
Then, the number is 6