Steven has some money. If he spends $9, then he will have 3/5 of the amount he started with.

Steven has some money. If he spends $9, then he will have 3/5 of the amount he started with.

Let the amount Steven started with be s. We're given:
s - 9 = 3s/5

Multiply each side through by 5 to eliminate the fraction:
5(s - 9) = 5(3s/5)

Cancel the 5's on the right side and we get:
5s - 45 = 3s

To solve for s, we type this equation into our search engine and we get:
s = 22.5