Phân tích đa thức thành nhân tử
a) x3 - 2x2 + x
= x (x2 - 2x + 1) = x (x - 1)2
b) a4 + a3 + a3b + a2b
= a3 (a + 1) + a2b (a + 1) = (a + 1) (a3 + a2b)
= a2 (a + 1)(a + b)
c) a3 + 3a2 + 4a + 12
= a2 (a + 3) + 4 (a + 3)
= (a + 3) (a2 + 4)
a. = x( x\(^2\) - 2x + 1 )
d . = ( x - y + 4 +2x + 3y - 1 ) ( x - y + 4 - 2x - 3y + 1 )
= ( 3x + 2y + 3 ) ( -x - 4y + 5 )
e. = (3x)\(^3\) + 3.(3x)\(^2\).1 + 3.3x.1\(^2\) + 1\(^3\)
= ( 3x + 1 )\(^3\)
\(x^3-2x^2+x=x\left(x^2-2x+1\right)=x\left(x-1\right)^2\)
\(a^4+a^3+a^3b+a^2b=a^3\left(a+b\right)+a^2\left(a+b\right)=\left(a+b\right)\left(a^3+a^2\right)=a^2\left(a+b\right)a\)
\(c,a^3+3a^2+4a+12=a^2\left(a+3\right)+4\left(a+3\right)=\left(a^2+4\right)\left(a+3\right)\)
\(d,\left(x-y+4\right)^2-\left(2x+3y-1\right)=\left(x-y+2x+3y-1+4\right)\left(x-y-2x-3y+1+4\right)=\left(3x+2y+3\right)\left(-x-4y+5\right)\)
\(e,27x^3+27x^2+9x+1=\left(27x^3+1\right)+\left(27x^2+9x\right)=\left(3x+1\right)\left(9x^2-3x+1\right)+9x\left(3x+1\right)=\left(3x+1\right)\left(9x^2+6x+1\right)=\left(3x+1\right)^3\)
\(f,x^3z+x^2yz-x^2z^2-xyz^2=x^2z\left(x-z\right)+xyz\left(x-z\right)=\left(x-z\right)\left(x^2z+xyz\right)=\left(x-z\right)xz\left(x+y\right)\)