To change from meters per day into kilometers per year, you just have to change from meters to kilometers and from days to years. You just multiply/divide by the unit conversions (for example, 1000 meters per kilometer) in a way that cancels out the units and leaves just kilometers and years:
The meters on the top of the first section cancels out with the meters on the bottom of the second section, and the days on the bottom of the first section cancels out with the days on the top of the last section, leaving just kilometers and years. The answer is 7.3 kilometers per year.
58 stamps is the number she gets each week. So if she went for one week, 58*1=58. 58*2=116 and so on. Because we don't know the exact number of weeks, we say 58w or 58*w because you multiply however many number of weeks she collects.
The graph of y = 2x+1 will never go through the point (2,3) because the graph is a linear function which means it goes in a straight line. Knowing this, when y = 3, x = 5 this means that the function will never hit (2,3)