Q6) In the following, solve the linear system by Gaussian elimination.
a) Solve the system of equations:
x₁ + x₂ + 2x₃ = 8
-x₁ - 2x₂ + 3x₃ = 1
3x₁ - 7x₂ + 4x₃ = 10

b) Solve the system of equations:
x - y + 2z - w = -1
2x + y - 2z - 2w = -2
-x + 2y - 4z + w = 1
3x - 3w = -3