Step-by-step explanation:
An + c = d
an=d-c
a=(d-c)/n is your answer
*REVERSE THE CHANGE QUESTION*
100% + 20% = 120% = $252
252 / 120 = $2.10 = 1%
100% = 2.1 x 100 = $210
Answer: $6.50
If the number is below 5 (so 1-4) you round down. If its above 5 (5-9), you round up.
E.G. 78.89
Round this to the nearest 10th, you'll get 78.90