a) 3x.( 5x ² – 2x – 1 ) b) ( x ² + 2xy – 3 ) . ( -xy ) c) c. 1/2 x2y ( 2×3 – 2/5 xy2 -1) 09/09/2021 Bởi Alaia a) 3x.( 5x ² – 2x – 1 ) b) ( x ² + 2xy – 3 ) . ( -xy ) c) c. 1/2 x2y ( 2×3 – 2/5 xy2 -1)
`a, 3x(5x^2 – 2x – 1)` `= 15x^3 – 6x^2 – 3x` `b, (x^2 + 2xy – 3)(-xy)` `= -x^3y – 2x^2y^2 + 3xy` `c, 1/2 x^2y(2x^3 – 2/5 xy^2 – 1)` `= x^5y – 1/5 x^3y^2 – 1/2 x^2y` Bình luận
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 c. 1/2 x2y ( 2×3 – 2/5 xy2 -1) = x^5 – 1/5 x³y³ – 1/2 x²y Bình luận
`a, 3x(5x^2 – 2x – 1)`
`= 15x^3 – 6x^2 – 3x`
`b, (x^2 + 2xy – 3)(-xy)`
`= -x^3y – 2x^2y^2 + 3xy`
`c, 1/2 x^2y(2x^3 – 2/5 xy^2 – 1)`
`= x^5y – 1/5 x^3y^2 – 1/2 x^2y`
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
c. 1/2 x2y ( 2×3 – 2/5 xy2 -1)
= x^5 – 1/5 x³y³ – 1/2 x²y