Stevelyn went to Amelia's and bought x packages of spaghetti for $2 each and y jars of pasta sauce for $3 each and spent a total of $18. But upon returning home Stevelyn had pasta sauce already but was out of parmesan cheese. Stevelyn returned to Amelia's and bought x containers of parmesan cheese for $4 each and returned the pasta sauce bought on the first trip and still spent $18. The system of equations shown below represents the amounts, in dollars, Stevelyn spent on the two trips to Amelia's.
How many boxes of spaghetti did Stevelyn buy on the first trip?
How many jars of pasta sauce did Stevelyn buy on the first trip?
