The number (x) in: "5 more than three times a number is 17" is what we are solving here.
In other words, you are looking for a number (x) that if you multiply it by three (same as three times) and then add 5, you get 17.
To solve this, you first write the problem as an algebra equation as follows: 3x + 5 = 17
Then you solve the equation by subtracting 5 from both sides, and then divide both sides by 3. Here is the math to illustrate better:
3x + 5 = 17
3x + 5 - 5 = 17 - 5
3x = 12
3x/3 = 12/3
x = 4
Answer = 4