Phân tích đa thức thành nhân tử
a. 3x^2 - 6x + 9x^2 + x^3
b. 10x( x-y ) - 6y( y-x )
c. 3x^2 + 5y - 3xy - 5x
d. 3y^2 - 3z^2 + 6xy
e. 27 + 27x + 9x^2
f. 8x^3 - 12x^2y + 6xy^2 - y^3
g. X^3 + 8y^3
h. 16x^3 + 54y^3
i. x^2 - 25 - 2xy + y^2
k. x^5 - 3x^4 + 3x^3 - x^2
\(10x\left(x-y\right)-6y\left(y-x\right)\)
\(=10x\left(x-y\right)+6x\left(x-y\right)\)
\(=\left(10x+6x\right)\left(x-y\right)\)
\(c,3x^2+5y-3xy-5x\)
\(=\left(3x^2-3xy\right)+\left(5y-5x\right)\)
\(=3x\left(x-y\right)-5\left(x-y\right)\)
\(=\left(3x-5\right)\left(x-y\right)\)
\(e,27+27x+9x^2=3\left(9+9x+x^2\right)\)
\(f,8x^3-12x^2y+6xy^2-y^3\)
\(=\left(2x-y\right)^3\)
\(g,x^3+8y^3=x^3+\left(2y\right)^3\)
\(=\left(x+2y\right)\left(x^2-2xy+4x^2\right)\)
\(i,x^2-25-2xy+y^2\)
\(\left(x^2-2xy+y^2\right)-25=\left(x-y\right)^2-5^2\)
\(=\left(x-y-5\right)\left(x-y+5\right)\)