If I spend two thirds of my money and have 10 dollars change how much did I have to start with
(2/3)x + 10 = x
10 = x - (2/3)x
10 = 1/3x
10 / (1/3) = x
10 * 3 = x
? = x
10 = x - (2/3)x
10 = 1/3x
10 / (1/3) = x
10 * 3 = x
? = x