a)m^4 – m/2m^2+2m+ b)ab^2+a^3-a^2b/a^3b+b^4 c)xy+1-x-y/y+z-1-yz d)ax+ay-bx-by/ax-ay-bx+by e)a^2+b^2-c^2+2ab/a^2-b^2+c^2+2ab f)a^2-b^2/a^2-a-b-b^2

0 bình luận về “a)m^4 – m/2m^2+2m+ b)ab^2+a^3-a^2b/a^3b+b^4 c)xy+1-x-y/y+z-1-yz d)ax+ay-bx-by/ax-ay-bx+by e)a^2+b^2-c^2+2ab/a^2-b^2+c^2+2ab f)a^2-b^2/a^2-a-b-b^2”

1. Đáp án:

    

   Giải thích các bước giải:

   a, (m^4 – m)/(2m^2 + 2m + 2)
   = m.(m^3 – 1)/2.(m^2 + m + 1)
   = m.(m – 1)(m^2 + m + 1)/2.(m^2 + m + 1)
   = m(m – 1)/2
   = (m^2 – m)/2

   b, ab^2 + a^3 – a^2 b / a^3b + b^4
   = a(b^2 + a^2 – ab)/b.(a^3 + b^3)
   = a(b^2 + a^2 – ab)/b.(a + b)(b^2 + a^2 – ab)
   = a/b.(a + b)
   ​= a/(ab + b^2)

   c, (xy + 1 – x – y) /(y + z – 1 – yz)
   = [(xy – x) – (y – 1)]/[(y – 1) – (yz – z)]
   = [x(y – 1) – (y – 1)]/[(y – 1) – z(y – 1)]
   = (y – 1)(x – 1)/(y – 1).(1 – z)
   = (x – 1)/(1 – z)

   d, (ax + ay – bx – by)/ (ax – ay – bx + by)
   = [a(x + y) – b(x + y)]/[a(x – y) – b(x – y)]
   = (x +  y)(a – b)/(a – b)(x – y)
   = (x + y)/(x-y)

    

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