Consider the linear system 3x1 -6x2 +3x3 +9x4 3 2x1 -3x2 +3x3 +4x4 4 -3x1 +7x2 -2x3 -10x4 -1 Bring the augmented matrix of the system to row echelon form, and state which of the variables are leading...

Extracted text: Consider the linear system 3x1 -6x2 +3x3 +9x4 3 2x1 -3x2 +3x3 +4x4 4 -3x1 +7x2 -2x3 -10x4 -1 Bring the augmented matrix of the system to row echelon form, and state which of the variables are leading variables and which are free variables. Select one: a. x1, x2 and x4 are the leading variables, while x3 is the free variable b. x1 and x4 are the leading variables, while x2 and x3 are the free variables C. X1, x2 and x3 are the leading variables, while x4 is the free variable O d. x1 and x2 are the leading variables, while x3 and x4 are the free variables e. x1 and æ3 are the leading variables, while x2 and æ4 are the free variables