Root 25-2(3+4*(-2)) whole square

Can someone explain the elimination method to me for this problem?

Solve the word problem. the table shows the low outside temperatures for monday, tuesday, and wednesday. by how many degrees did the low temperature increase from monday to tuesday? this function table shows the outside temperature for a given a. 21.1⁰ b. 8.6⁰ c. 4.9⁰ d. 3.9⁰(the picture is the graph the the question is talking about.)

What point is the projection of q on a) r b) s c) t