Question

raphael paid $648 for a camera during a 20% off sale. what was the​ camera's regular​ price?

Answer 1

100% – 20% = 80%

Solution 1 :
100% = x
80% = $648
80x = 64800
x = $810

Solution 2 :
80% • x = $648
80/100 • x = 648
80x = 64800
x = $810

Check :
20% × $810
= 20/100 × $810
= $648

The camera's regular price is $810.