Question

1 . a) \(x^2-y^2+3x^2z+6xyz+3y^2z\)

b) \(x^2+xy+5-6x-y\)

2 . Cho biểu thức P = \(4x^2-8x+1+b+2\) . có giá trị nhỏ nhất bằng = 2 . Tính \(a^3+b^3+3ab\left(a+b\right)+2019\)

3 . Làm tính chia : \(\left(x^3-3x^2+3x-1\right)\left(2y^2+4y+2\right):\left(x-1\right)\left(y+1\right)^2\)

Answer 1

1. b, \(x^2+xy+5-6x-y\)

\(=\left(x^2-6x+5\right)+\left(xy-y\right)\\ =\left(x-1\right)\left(x-5\right)+y\left(x-1\right)\\ =\left(x-1\right)\left(x+y-5\right)\)

Answer 2

1. a, \(x^2-y^2+3x^2z+6xyz+3y^2z\)

\(=\left(x^2-y^2\right)+\left(3x^2z+6xyz+3y^2z\right)\\ =\left(x-y\right)\left(x+y\right)+3z\left(x^2+2xy+y^2\right)\\ =\left(x-y\right)\left(x+y\right)+3z\left(x+y\right)^2\\ =\left(x+y\right)\left[x-y+3z\left(x+y\right)\right]\\ =\left(x+y\right)\left(x-y+3xz+3yz\right)\)