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

zane and his little brother made up a game using coins. they flip the coins towards a cup and receive points for everyone that makes it in. zane starts with 20 points, and his little brother starts with 17 points. zane gets 1 point for every successful shot, and his brother, since he is younger, gets 4 points for each successful shot. eventually, the brothers will have a tied score in the game. how many points will they both have? how many additional shots will each brother have made?