First you need to make a multiplier for 100-2.1%, to do this you minus the values and divide it by 100:
100-2.1 = 97.9
97.9/100 = 0.979
Then you multiply all the questions by it:
$45 * 0.979 = $44.055
$765 * 0.979 = $748.935
$1300 * 0.979 = $1272.7
Hope this helps! :)
You do 3/5 minus 3/5 which cancels out to 0. Then you do 6 minus 4 which is 2. The answer is 2.
There needs to be values to answer the question.