Question

phan tich da thuc thanh nhan tu 

a/ 3x²+6xy+3y²-3z²

b/ 4y²-5y-6

c/ 3x-9xy-9y²+6y-1

d/ x⁴+x²y²+y⁴

Answer 1

a ) = 3 ( x^2 + 2xy + y^2 - z^2 )

     = 3  [ ( x  +  y)^2 - z^2] 

      = 3 ( x + y - z)( x  + y + z)

b) 4 y^ 2 - 5 y - 6 = 4y^2 - 8y + 3y - 6 = 4y ( y-  2 ) + 3 ( y-  2 ) = (  4y +3 )( y - 2 )

 

d) x^4 + x^2y^2 + y^4 = x^4 +  2 x^2y^2 + y^4 - x^2y^2 = ( x^2 + y^2 )^2 - (xy)^2 = ( x^2 - xy + y^ 2)( x^2 + xy + y^2)