To paint his house, Samuel bought 2 cans of paint and one roller for $30. When friends came over to help, he went back to the store and bought three more cans of paint and two more rollers for $50. How much did he pay for a roller?
Let the price of a can of paint be
Let the price of a roller be
Multiply everything in
Consider equation(2). I can costs $10 so we have:
Subtract $30 from both sides
Divide both sides by 2