Câu 1 : a ) x ² ( x – 2x ³ ) b ) ( x ² + 1 ) ( 5x – x ) c ) ( x – 2 ) ( x ² + 3x – 4 ) d ) ( x – 2 ) ( x – x ² + 4 )

0 bình luận về “Câu 1 : a ) x ² ( x – 2x ³ ) b ) ( x ² + 1 ) ( 5x – x ) c ) ( x – 2 ) ( x ² + 3x – 4 ) d ) ( x – 2 ) ( x – x ² + 4 )”

1. a ) x ² ( x – 2x ³ )

   = x³ – 2x^5

   b ) ( x ² + 1 ) ( 5x – x )

   = 5x³ – x³ + 5x – x 

   c ) ( x – 2 ) ( x ² + 3x – 4 )

   = x³ + 3x² – 4x – 2x² + 5x – 6

   d ) ( x – 2 ) ( x – x ² + 4 )

   = x² – x³ + 4x – 2x – 2x² + 6

    

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2. Đáp án:

    

   Giải thích các bước giải:

   a) `x^2(x-2x^3)=x^3-2x^5`

   b) `(x^2+1)(5x-x)=5x^3-x^3+5x-x=4x^3+4x`

   c) `(x-2)(x^2+3x-4)=x^3+x^2-10x+8`

   d) `(x-2)(x-x^2+4)=-x^3+3x^2+2x=8`

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