To solve this problem, you should set up an equation, and let the variable x represent the number that you are trying to figure out.
Thus, your equation would be:
3x + 7 = 52
To simplify this equation, we should subtract 7 from both sides to get the variable term isolated.
3x + 7 - 7 = 52 - 7
3x = 45
Next, we should divide both sides by 3 to cancel out the coefficient of the variable x.
3x/3 = 45/3
x = 15
Therefore, the number you are looking for is 15.
Hope this helps! :)