Solve 9 raise to power 2 x - 3 / 3 raise to power x + 3 equals to 1​

Emily works as a painter. for each job, it takesher 30 minutes to prepare an interior wall ofa house before she paints and 2 minutes persquare yard to paint that will. the graph belowshows the total time it would take her to do a job,based on the total area of the wallhow long does it take her to do a job when she paints a wall with an area of 15 square yards?