Answer: 80.58 dollars
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Work Shown:
x = amount of money collected before tax is added
3% = 3/100 = 0.03
3% of x = 0.03x = amount of tax
x + 0.03x = adding on tax to original amount
1.03x = amount after tax is added
1.03x = 2766.58
x = 2766.58/1.03
x = 2686 is the amount of money before the 3% sales tax is added
0.03x = 0.03*2686 = 80.58 is the amount of sales tax collected
As a check,
2686+80.58 = 2766.58
which confirms our answer