Question 4: Solve the following system of equations using the elimination method. Apply operations that respect equivalency until you have a linear system that can be solved with a back-substitution. Operations and intermediate systems should be clearly stated. -x1 + 2x2 - 2x3 + 3x4 = 1 2.x1 2x2 + 3x3 4x4 1 - %3D I1 - X2 + x3 - X4 = -1 -2x1 +3x2-3x3 +3x4 = 4 %3D