Use Newton's Method to Approximate All Real Roots Of $x ^ { 4 } + x ^ { 3 } - 3 x ^ { 2 } + 4 x - 28 = 0$

Use Newton's Method to approximate all real roots of $x ^ { 4 } + x ^ { 3 } - 3 x ^ { 2 } + 4 x - 28 = 0$ .