Larry saves 15% of his annual salary for retirement. This year his salary was $2000 more than last year and he saved $3300. What was his salary last year

To answer this question, we let x be Larry's salary last year. With this representation, Larry's current salary is x + 2000. Considering that he saved up 3300 this year, that is,

3300 = 0.15 (x + 2000)

The value of x from the equation above is 21800. His salary last year is $21,800.