21.30^ 65/1000 = 1,3845 ( sales tax )
21.30-1,3845= 19.91 ( shirt )
I got 65/1000 is because it’s a decimal if you have a decimal and you want to make it to a whole number you have to times the denominator and the numerator with the same number and when u find the tax price u just substract the after tax price of the shirt
