phân tích đa thức sau thành nhân tử
a) \(a\left(b+c\right)\left(b^2-c^2\right)+b\left(a+c\right)\left(a^2-c^2\right)+c\left(a+b\right)\left(a^2-b^2\right)\)
b) \(\left(x^2+x+1\right)\left(x^2+x-2\right)-12\)
c) \(\left(x^2+2x\right)^2+9x^2+18x+20\)
d) \(\left(x^2+4x+8\right)^2+3x\left(x^2+4x+8\right)+2x^2\)
Các bn giỏi giúp mk đi,đg gấp !!!
c: \(\left(x^2+2x\right)^2+9x^2+18x+20\)
\(=\left(x^2+2x\right)^2+9\left(x^2+2x\right)+20\)
\(=\left(x^2+2x+4\right)\left(x^2+2x+5\right)\)
d: \(\left(x^2+4x+8\right)^2+3x\left(x^2+4x+8\right)+2x^2\)
\(=\left(x^2+4x+8+2x\right)\left(x^2+4x+8+x\right)\)
\(=\left(x^2+5x+8\right)\left(x^2+6x+8\right)\)
\(=\left(x^2+5x+8\right)\left(x+4\right)\left(x+2\right)\)