Explain how to write and solve the equation.Sonja paid $12.50 to see a movie and has $30 left. How much money did Sonja have before she paid for the movie?

Answer:

To find the original amount of money Sonja had, let s represent the starting amount. Since the movie cost $12.50 and she had $30 left, you can write the subtraction equation s - 12.50 = 30 (or 30 = s - 12.50). To solve for s, use the inverse operation of subtraction by adding 12.50 to both sides. This gives s = 42.50, meaning Sonja originally had $42.50.