Multiply: (x+1)(x+2)(x+3)(x + 1)(x + 2)(x + 3)(x+1)(x+2)(x+3).
x3+6x2+11x+6x^3 + 6x^2 + 11x + 6x3+6x2+11x+6
x3+6x2+6x+6x^3 + 6x^2 + 6x + 6x3+6x2+6x+6
x3+3x2+6x+6x^3 + 3x^2 + 6x + 6x3+3x2+6x+6
x3+9x+6x^3 + 9x + 6x3+9x+6