Write a system of equations to describe the situation below, solve using substitution, and fill in the blanks. two classmates have decided to read all the volumes in a popular series of books. jane has already read 6 volumes and will continue to read new ones at a rate of 3 volumes per week. sarah, who hasn't started reading the series yet, will read 4 volumes per week. at some point, sarah will catch up with jane and they will be reading the same book. how long will that take? how many volumes will each girl have read by then? in weeks, the girls will each have read volumes in the series.