a) Write the following system of equations in matrix form.
3x₁ + 5x₂ + 7x₃= 8
2x₁ -x₁ + x₃ = 4
x₁+ 6x₂ -2x₃ = 6
(b) Rewrite the matrix equation in part (a) to reflect the operation of bringing the right side over to the left side (so that the right sides are now O's).