X+3/x+1+2x-1/x-1+x+5/x²-1

2 bình luận về “X+3/x+1+2x-1/x-1+x+5/x²-1”

1. (x+3)/(x+1)+(2x-1)/(x-1)+(x+5)/(x^2-1)(ĐK:x\ne1; x\ne-1)

   =(x+3)/(x+1)+(2x-1)/(x-1)+(x+5)/((x-1).(x+1))

   =((x+3).(x-1)+(2x-1).(x+1)+(x+5))/((x-1).(x+1))

   =(x^2-x+3x-3+2x^2+2x-x-1+x+5)/((x-1).(x+1))

   =(3x^2+4x+1)/((x-1).(x+1))

   =(3x^2+3x+x+1)/((x-1).(x+1))

   =(3x.(x+1)+(x+1))/((x-1).(x+1))

   =((x+1).(3x+1))/((x-1).(x+1))

   =(3x+1)/(x-1)

    

   Trả lời
2. [x+3]/[x+1] + [2x-1]/[x-1] + [x+5]/[x^2-1] (ĐK: x \ne +-1)

   = [x+3]/[x+1] + [2x-1]/[x-1] + [x+5]/[(x-1)(x+1)]

   = [(x+3)(x-1)]/[(x-1)(x+1)] + [(2x-1)(x+1)]/[(x-1)(x+1)] + [x+5]/[(x-1)(x+1)]

   = [x^2+2x-3+2x^2+x-1+x+5]/[(x-1)(x+1)]

   = [3x^2+4x+1]/[(x-1)(x+1)]

   = [(3x^2+3x)+(x+1)]/[(x-1)(x+1)]

   = [3x(x+1)+(x+1)]/[(x-1)(x+1)]

   = [(x+1)(3x+1)]/[(x-1)(x+1)]

   = [3x+1]/[x-1]

   @BadMo od

   Trả lời