a, 2x(2x-1)^2-3x(x+3)(x-3)-4x(x+1)^2 b, (a-b+c)^2-(b-c)^2+2ab-2ac c, (3x+1)^2-2(3x+1)(3x+5)+(3x+5)^2 d, (2x+y)^2-(y-2x)^2 e, (3x+2)^2+2(2+3x)(1-2

0 bình luận về “a, 2x(2x-1)^2-3x(x+3)(x-3)-4x(x+1)^2 b, (a-b+c)^2-(b-c)^2+2ab-2ac c, (3x+1)^2-2(3x+1)(3x+5)+(3x+5)^2 d, (2x+y)^2-(y-2x)^2 e, (3x+2)^2+2(2+3x)(1-2”

1. Đáp án: a) ( a + b + c ) 2 + ( a + b – c ) 2 -2 x ( a+b) 2

   2a+2b+2x+2a+2b-2c-2.(2a+2b)

   2a+2b+2c+2a+2b-2c-4a-4b

   4a+4b-4a-4b=0

   b) 2x.( 2x -1 ) 2 -3x.( x+3 )( x-3) – 4x.(x+1).2

   2x.(4x-2)-3×2-9x-3×2+9x-4x(2x+2)

   8×2-4x-3×2-9x-3×2+9x-8×2-8x

   -12x-3×2

   c) ( a-b+c).2 -(b-c).2 + 2ab – 2ac

   2a-2b+2c-2b+2c+2ab-2ac

   2a-4b+4c+2ab-2ac

   d) (3x+1).2 – 2(3x+1)( 3x+5 )+(3x+5).2

   6x+2-6x-2-6x-10+6x+10=0

   Giải thích các bước giải:

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