a, \(16x^3+54y^3=2\left(8x^3+27y^3\right)=2\left(2x+3y\right)\left(4x^2-12xy+9y^2\right)\)
b, \(5x^2\left(x-1\right)+10xy\left(x-1\right)-5y^2\left(1-x\right)\)
\(=\left(5x^2+10xy+5y^2\right)\left(x-1\right)=5\left(x^2+2xy+y^2\right)\left(x-1\right)=5\left(x+1\right)^2\left(x-1\right)\)
bổ sung phần a hộ mình
\(=2\left(2x+3y\right)\left(4x^2-12xy+9y^2\right)=2\left(2x+3y\right)\left(2x-3y\right)^2\)
a) \(16x^3+54y^3=2\left(8x^3+27y^3\right)=2\left(2x+3y\right)\left(4x^2-6xy+9y^2\right)\)
b) \(5x^2\left(x-1\right)+10xy\left(x-1\right)-5y^2\left(1-x\right)\)
\(=5x^2\left(x-1\right)+10xy\left(x-1\right)+5y^2\left(x-1\right)=\left(5x^2+10xy+5y^2\right)\left(x-1\right)\)
\(=\left(\sqrt{5}x+\sqrt{5}y\right)^2\left(x-1\right)\)
sửa phần a hộ mình lại => hấp tấp quá
a, \(16x^3+54y^3=2\left(8x^3+27y^3\right)=2\left(2x+3y\right)\left(4x^2-6xy+9y^2\right)\)
a. 16x3 + 54y3 = 2 ( 8x3 + 27y3 ) = 2 [ ( 2x )3 + ( 3y )3 ]
= 2 ( 2x + 3y ) [ ( 2x )2 + ( 2x )( 3y ) + ( 3y )2 ] = 2 ( 2x + 3y ) ( 4x2 + 6xy + 9y2 )
b. 5x2 ( x - 1 ) + 10xy ( x - 1 ) - 5y2 ( 1 - x )
= 5x2 ( x - 1 ) + 10xy ( x - 1 ) + 5y2 ( x - 1 )
= ( x - 1 ) ( 5x2 + 10xy + 5y2 )
= 5 ( x - 1 ) ( x2 + 2xy + y2 )
= 5 ( x - 1 ) ( x + y )2