Question 1170986
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Let x be the number of boxes of candy sold.
Then (175-x) is the number of boxes of popcorn sold (because the total number of items sold was 175).<br>
The total cost of the items, at $2.50 for each box of candy and $5 for each bag of popcorn, was $687.50:<br>
{{{2.50(x)+5(175-x) = 687.50}}}<br>
It sounds as if an equation is what you wanted, so I'll end my response there.<br>