The anwser would be -15
3 x (-5) = -15
You do 28, which is the original cost, then you take that 15% off to do that you multiply 28×.15 and you get 4.2 and subtract that from original cost and you get 23.8 then to get the cost after tax you do 23.8×.0675 and you get 1.6 then you add that to 23.8 and get 25.4 dollars
If you have to multiply each decimal by 100 so it’ll make more sense and sort from there :)
