\(a,=\left(3x^3+x^2+9x^2+3x-3x-1-4\right):\left(3x+1\right)\\ =\left[\left(3x+1\right)\left(x^2+3x-1\right)-4\right]:\left(3x+1\right)\\ =x^3+3x-1\left(dư.-4\right)\\ b,=\left(x^2-2x+1-2x+6\right):\left(x^2-2x+1\right)\\ =\left[x^2-2x+1-2x+6\right]:\left(x^2-2x+1\right)\\ =1\left(dư.-2x+6\right)\)


