Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

222-9+11+12:2*14+14 = ? ( )

Toán Lớp 8: tính x+3/x^2-4 nhân 8-12x+6x^2-x^3/9x +27

Toán Lớp 8: tính
x+3/x^2-4 nhân 8-12x+6x^2-x^3/9x +27

Comments ( 2 )

  1. Giải đáp:
    $\begin{array}{l}
    \dfrac{{x + 3}}{{{x^2} – 4}}.\dfrac{{8 – 12x + 6{x^2} – {x^3}}}{{9x + 27}}\\
     = \dfrac{{x + 3}}{{\left( {x – 2} \right)\left( {x + 2} \right)}}.\dfrac{{{{\left( {2 – x} \right)}^3}}}{{9\left( {x + 3} \right)}}\\
     = \dfrac{{ – {{\left( {2 – x} \right)}^2}}}{{\left( {x + 2} \right).9}}\\
     = \dfrac{{ – 4 + 4x – {x^2}}}{{9x + 18}}
    \end{array}$

  2. Giải đáp:
    \frac{x+3}{x^2-4}xx\frac{8-12x+6x^2-x^3}{9x+27}
    = \frac{x+3}{(x-2)(x+2)}xx\frac{(2-x)^3}{9(x+3)}
    = \frac{1}{(x-2)(x+2)}xx[-\frac{(x-2)^3}{9}]
    = \frac{1}{x+2}xx[-\frac{(x-2)^2}{9}]
    = -\frac{(x-2)^2}{(x+2)xx9}
    = -\frac{x^2-4x+4}{9x+18}

Leave a reply

222-9+11+12:2*14+14 = ? ( )

About Kim Dung