Toán Lớp 8: thực hiện phép tính
x/(x+4) + (x-1)/x -2
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Toán Lớp 8: thực hiện phép tính
x/(x+4) + (x-1)/x -2
Comments ( 2 )
DK:x \ne \left\{ { – 4;0} \right\}\\
\dfrac{x}{{x + 4}} + \dfrac{{x – 1}}{x} – 2\\
= \dfrac{{{x^2} + \left( {x – 1} \right)\left( {x + 4} \right) – 2x\left( {x + 4} \right)}}{{x\left( {x + 4} \right)}}\\
= \dfrac{{{x^2} + {x^2} + 3x – 4 – 2{x^2} – 8x}}{{x\left( {x + 4} \right)}}\\
= \dfrac{{ – 5x – 4}}{{x\left( {x + 4} \right)}}
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