Find last year's salary if after a 4% raise , this year's salary is $44,200. .

The current salary is  $44,200. In this case, the percent increase is 4%. The percent increase serves like an investment in which the interest is compounded. The formula that applies here is current = previous *( 1.04)^n where n is 1. Last year's salary is $42,500

Subtracting is the opposite of adding