Rút gọn các biểu thức `a) 2x ( x^2 – 5x + 10 ) + 10 ( x^2+3x+2) -2x(x^2 + 9 )` `b) (3x^5 – 10x^4 + 7x^3 ) : x^3 -2 ( x^2 – 2x

1 bình luận về “Rút gọn các biểu thức `a) 2x ( x^2 – 5x + 10 ) + 10 ( x^2+3x+2) -2x(x^2 + 9 )` `b) (3x^5 – 10x^4 + 7x^3 ) : x^3 -2 ( x^2 – 2x”

1. a) 2x ( x^2 – 5x + 10 ) + 10 ( x^2+3x+2) -2x(x^2 + 9 )

   = 2x xx x^2 – 2x xx 5x + 2x xx 10 + 10xx x^2 + 10 xx 3x + 10 xx 2 – 2x xx x^2 -2x xx 9

   = 2x^3 -10x^2 + 20x + 10x^2 + 30x +20 – 2x^3 -18x

   = (2x^3-2x^3) + (-10x^2+10x^2) + (20x + 30x-18x) + 20

   = 32x+20

   b) (3x^5 – 10x^4 + 7x^3) : x^3 – 2 (x^2 – 2x + 1)

   = (3x^5) : x^3 – (10x^4) : x^3 + (7x^3) :x^3 – 2 xx x^2 + 2xx 2x -2

   = 3x^2 – 10x – 2x^2 + 4x – 2

   = (3x^2 – 2x^2) +(-10x + 4x) -2

   = x^2 – 6x -2

   $@Thwantobethebest$

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