Same rate implies linear increase, which we are told is 9000/year
2010: profit of 45,000
2011: profit of 45,000+9000 = 54,000
2012: profit of 54,000 + 9000 = 63,000
2013: profit of 63,000 + 9000 = 72,000
2014: profit of 72,000 + 9000 = 81,000 <<<< This is the answer
Note that we could have multiplied to get the same answer, but this way avoids fencepost problems: Okay because just a few years