Write a system of equations to describe the situation below, solve using substitution, and fill in the blanks.

Amy has punch cards for her favorite tea house and her favorite coffee shop. She currently has 7 punches on the tea punch card and 11 punches on the coffee punch card. Given her regular routine, she consistently earns 5 new punches per week on the tea punch card and 1 on the coffee punch card. Before too long, Amy will have the same number of punches on each card. How long will that take? How many punches will Amy have on each card?