The larger of 2 numbers is 1 more than 3 times the smaller number

The larger of 2 numbers is 1 more than 3 times the smaller number.

Let the larger number be l. Let the smaller number be s. The algebraic expression is:

3 times the smaller number is written as:
3s

1 more than that means we add 1
3s + 1

Our final algebraic expression uses the word is meaning an equation. So we set l equal to 3s + 1
l = 3s + 1