Students graphed the growth rate over several weeks of two plants in their classroom. The equations of both plants are given where x represents the time in weeks and y represents the heights of the plants in inches. Plant a: y = 1. 8x + 3. 1 plant b: y = 2. 3x + 1. 9 approximately how many weeks will it take for both plants to reach the same height? round your answer to the nearest tenth.