Margo can purchase tile at a store for $0.59 per tile and rent a tile saw for $21. At another store she can borrow the tile saw for free if she buys tiles there for $1.29 per tile. How many tiles must she buy for the cost to be the same at both stores?

Answer 1

If the cost is the same for x tiles, then you have
0.59x + 21 = 1.29x