The gardening store sells clay flower pots, which hold 1 liter of dirt, and ceramic flower pots, which hold 5 liters. Matthew bought 27 flower pots, which will hold a total of 63 liters of dirt. How many of each type of flower pot did he buy?

Let x = the number of clay pots. Since Matthew bought 27 pots in total, the number of ceramic pots he bought is 27-x.

63 liters = (1 liter)*(x clay pots) + (5 liters)*(27-x ceramic pots)

63 = x + 135 - 5x

63 = 135 - 4x

Solve for x (clay pots), then 27-x (ceramic pots).