Question 567320
Let
Original bill = $x


10% of x = 10/100 (x)
10% of x = 1/10 (x)
10% of x = x/10

Bill = original bill - 10% discount 
509375=x-x/10
509375=(10x-x)/10
10* 509375=(10x-x)
5093750=9x
5093750/9=9x/9
565972.20=x
x=565972.20

Original bill = $565972.20