The amount of last year sales is $ 528400
Solution:
Let "x" be the amount of last year sales
Given that,
The total sales at Office Products this year are $713,340, which is 35% more than last year’s sales
Therefore,
This year sales = 35 % more than last year sales
This year sales = 35 % of last year sales + last year sales
713340 = 35 % of x + x

Thus amount of last year sales is $ 528400