a) 3x.( 5x ² – 2x – 1 ) b) ( x ² + 2xy – 3 ) . ( -xy ) c) c. 1/2 x2y ( 2×3 – 2/5 xy2 -1)

0 bình luận về “a) 3x.( 5x ² – 2x – 1 ) b) ( x ² + 2xy – 3 ) . ( -xy ) c) c. 1/2 x2y ( 2×3 – 2/5 xy2 -1)”

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`

   Trả lời

2. 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

   Trả lời