Toán Lớp 8: x/x^2-2x-x^2+4x/x^3-4x-2/x^2+2x
phép trừ nha mn
Leave a reply
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.
Toán Lớp 8: x/x^2-2x-x^2+4x/x^3-4x-2/x^2+2x
phép trừ nha mn
Comments ( 1 )
DK:x \ne \left\{ { – 2;0;2} \right\}\\
\dfrac{x}{{{x^2} – 2x}} – \dfrac{{{x^2} + 4x}}{{{x^3} – 4x}} – \dfrac{2}{{{x^2} + 2x}}\\
= \dfrac{x}{{x\left( {x – 2} \right)}} – \dfrac{{{x^2} + 4x}}{{x\left( {x – 2} \right)\left( {x + 2} \right)}} – \dfrac{2}{{x\left( {x + 2} \right)}}\\
= \dfrac{{x\left( {x + 2} \right) – {x^2} – 4x – 2\left( {x – 2} \right)}}{{x\left( {x – 2} \right)\left( {x + 2} \right)}}\\
= \dfrac{{{x^2} + 2x – {x^2} – 4x – 2x + 4}}{{x\left( {x – 2} \right)\left( {x + 2} \right)}}\\
= \dfrac{{ – 4x + 4}}{{x\left( {x – 2} \right)\left( {x + 2} \right)}}
\end{array}\)