first, distribute the 100 to the (x-1) portion:
500 = 100x - 100
then, add 100 to both sides of your equation to get “x” alone on the right side:
500 + 100 = 100x - 100 + 100
600 = 100x
next, divide 100x by 100 and 600 by 100 to isolate a singular “x”:
600/100 = 100x/100
6 = x
therefore, x=6 is your solution