Toán Lớp 8: thực hiện phép tính: (1-2x/2x)+(2x/2x-1)+(1/2x-4x^2)

Question

Toán Lớp 8:  thực hiện phép tính: (1-2x/2x)+(2x/2x-1)+(1/2x-4x^2)

hothaibinh · Answer

text{Giải đáp v&agrave; giải th&iacute;ch c&aacute;c bước giải:}    frac{1-2x}{2x}+ frac{2x}{2x-1}+ frac{1}{2x-4x^2} $ text{(ĐK: x $ neq$ 0, x $ neq$ 0,5)}$   = frac{(1-2x)(2x-1)}{2x(2x-1)}+ frac{4x^2}{2x(2x-1)}+ frac{-1}{2x(2x-1)}   = frac{-(2x-1)^2+4x^2-1}{2x(2x-1)}   = frac{-(2x-1)^2+(2x-1)(2x+1)}{2x(2x-1)}   = frac{(2x-1)(2x+1-2x+1)}{2x(2x-1)}   = frac{2(2x-1)}{2x(2x-1)}   = frac{1}{x}

aivilanlan · Answer

1    &minus;    2    x        2    x        +        2    x        2    x    &minus;    1        +        1        2    x    &minus;    4      x      2             1-2x2x+2x2x-1+12x-4x2            =         (    1    &minus;    2    x    )      (    2    x    &minus;    1    )         2    x     (    2    x    &minus;    1    )         +        2    x    .2    x        2    x     (    2    x    &minus;    1    )         &minus;        1        2    x     (    2    x    &minus;    1    )            =(1-2x)(2x-1)2x(2x-1)+2x.2x2x(2x-1)-12x(2x-1)            =        &minus;    4      x      2      +    4    x    &minus;    1    +    4      x      2      &minus;    1        2    x     (    2    x    &minus;    1    )            =-4x2+4x-1+4x2-12x(2x-1)            =        &minus;    4    x    &minus;    2        2    x     (    2    x    &minus;    1    )            =-4x-22x(2x-1)            =        2     (    &minus;    2    x    &minus;    1    )         2    x     (    2    x    &minus;    1    )            =2(-2x-1)2x(2x-1)            =        &minus;    2    x    &minus;    1        x     (    2    x    &minus;    1    )