1. x^2 + 6x + 9 – 9y^2 2. 3(x-y) – 5x( y – x)

2 bình luận về “1. x^2 + 6x + 9 – 9y^2 2. 3(x-y) – 5x( y – x)”

1. Gửi bn

   

   Trả lời
2. 1.

   x^2+6x+9-9y^2

   = x^2+2.x.3+3^2-(3y)^2

   = (x+3)^2-(3y)^2

   = (x+3+3y)(x+3-3y)

   2.

   3(x-y)-5x(y-x)

   = 3(x-y)+5x(x-y)

   = (x-y)(3+5x)

   $#<33$

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