x²-xy-2y²

= x²-2xy+xy-2y²

=x(x-2y)+y(x-2y)

=(x-2y)(x+y)

\(x^2+4y^2+3x-6y=\left(x^2+3x\right)-\left(4y^2+6y\right)=x\left(x+3\right)-2y\left(2y+3\right)\)

x^3 - x + 3x^2y + 3xy^2 + y^3 - y

=x³+y³+3x²y+3xy²-x-y

=(x+y)(x²-xy+y²)+3xy(x+y)-(x+y)

=(x+y)(x²-xy+y²+3xy-1)

=(x+y)(x²+2xy+y²-1)

=(x+y)[(x+y)²-1]

=(x+y)(x+y-1)(x+y+1)

x^2 + 5x - 6

=x²-x+6x-6

=x.(x-1)+6.(x-1)

=(x-1)(x+6)

Ta có

a,    x²-x-y²-y

=x²-y²-(x+y)

=(x-y)(x+y) - (x+y)

=(x+y)(x-y-1)

b,   x²-2xy+y²-z²

=(x-y)²-z²

=(x-y-z)(x-y+z)

con bai 32, 33 neu ban tra loi duoc minh h them

nhanh nha

a) 7xy^2+5x^2y

= xy(7y+5x)

b) x^2+2xy+y^2-11x-11y

= (x^2+2xy+y^2)-(11x+11y)

=(x+y)^2-11(x+y)

=(x+y)(x+y-11)

a) 7xy² + 5x²y

= xy ( 7y + 5x )

b) x² + 2xy + y² - 11x - 11y

= ( x² + 2xy + y² ) - ( 11x + 11y )

= ( x + y )² - 11 ( x + y )

= ( x + y )( x + y - 11 )

\(4x^2-4y^2-4y-1\)

\(\Leftrightarrow4x^2-\left(2y+1\right)^2\)

\(\Leftrightarrow\left(2x-2y-1\right)\left(2x+2y+1\right)\)

P/s tham khảo nha

\(=4x^2-\left(4y^2+4y+1\right)\)

\(=4x^2-\left(4y^2+4y+1^2\right)\)

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

\(=\left(2x-2y-1\right)\left(2x+2y+1\right)\)

\(=\left(x^2+x\right)^2+3\left(x^2+x\right)+2-12\)

\(=\left(x^2+x\right)^2+3\left(x^2+x\right)-10\)

\(=\left(x^2+x+5\right)\left(x^2+x-2\right)\)

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