City planners are planning to build a new community pool. They agree that the pool will be rectangular in shape, but the proposed dimensions changed. At the most
recent meeting, it was determined that the width would remain at 12.3 meters but
that the length would increase by 4.3 meters. So, the pool would now cover an area
of 213.65 square meters.
Which equation can be used to determine the original length of the pool, I?