Toán a) 3x.( 5x ² – 2x – 1 ) b) ( x ² + 2xy – 3 ) . ( -xy ) 09/09/2021 By Piper a) 3x.( 5x ² – 2x – 1 ) b) ( x ² + 2xy – 3 ) . ( -xy )
a) 3x . ( 5x² – 2x – 1 ) = 3x . 5x² – 3x . 2x – 3x . ( -1) = 15x³ – 6x² – 3x b) ( x² + 2xy – 3 ) . ( -xy ) = ( -xy ) . ( x² + 2xy – 3 ) = ( -xy ) . x² + ( -xy ) . 2xy – ( -xy ) . ( -3 ) = ( -x³y )- 2x²y²+3xy Trả lời
a,3x(5$x^{2}$ -2x+1) =15$x^{3}$-6 $x^{2}$-3x b,($x^{2}$+2xy-3)(-xy) =-$x^{3}$y-2 $x^{2}$$y^{2}$+3xy Trả lời
a) 3x . ( 5x² – 2x – 1 )
= 3x . 5x² – 3x . 2x – 3x . ( -1)
= 15x³ – 6x² – 3x
b) ( x² + 2xy – 3 ) . ( -xy )
= ( -xy ) . ( x² + 2xy – 3 )
= ( -xy ) . x² + ( -xy ) . 2xy – ( -xy ) . ( -3 )
= ( -x³y )- 2x²y²+3xy
a,3x(5$x^{2}$ -2x+1)
=15$x^{3}$-6 $x^{2}$-3x
b,($x^{2}$+2xy-3)(-xy)
=-$x^{3}$y-2 $x^{2}$$y^{2}$+3xy