1. Consider the following system of two equations and two unknowns. [x + y = 2 [3x + y = 0 a) Solve the system using substitution. b) Solve the system using linear combination (a.k.a. the elimination method). c) Solve the system by graphing. (A sketch on regular paper is ok, but be sure to label any key points.) d) Check your work by confirming that your solutions for parts a, b, and c are the same! (Be sure to write a note on your paper that you completed this step.)