Final answer:
The question pertains to solving linear equations, graphing them, and finding the line of best fit for a set of data in statistics within the field of Mathematics for a High School level.
Step-by-step explanation:
The question involves the subject of Mathematics, specifically dealing with linear equations and systems of equations. There is also a part of the question that deals with statistics, namely calculating the line of best fit after removing an outlier from a set of data points for graphing purposes. By analyzing the content of the question, we can deduce that solving linear equations, sketching them on a diagram, and finding the line of best fit in statistics are the main components of this mathematical problem.