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

On the windowsill is a plant that is 40 centimeters tall. It is growing 3 centimeters per week. A second plant, which is 19 centimeters tall, is on the coffee table. It is growing 10 centimeters per week. Eventually the two plants will be the same height. How many weeks will that take? How tall will the plants be?