1
1
Hãy luôn nhớ cảm ơn và vote 5*
nếu câu trả lời hữu ích nhé!
14865
7666
Đáp án:
q) \(\dfrac{1}{x}\)
Giải thích các bước giải:
\(\begin{array}{l}
k)\dfrac{{\left( {4x + 5} \right)\left( {3x - 1} \right) - \left( {5 - 9x} \right)\left( {2x - 1} \right)}}{{\left( {2x - 1} \right)\left( {3x - 1} \right)}}\\
= \dfrac{{12{x^2} + 11x - 5 + 18{x^2} - 19x + 5}}{{\left( {2x - 1} \right)\left( {3x - 1} \right)}}\\
= \dfrac{{30{x^2} - 8x}}{{\left( {2x - 1} \right)\left( {3x - 1} \right)}}\\
m)\dfrac{{x + 6}}{{\left( {x - 2} \right)\left( {x + 2} \right)}} - \dfrac{2}{{x\left( {x + 2} \right)}}\\
= \dfrac{{x\left( {x + 6} \right) - 2\left( {x - 2} \right)}}{{x\left( {x - 2} \right)\left( {x + 2} \right)}}\\
= \dfrac{{{x^2} + 6x - 2x + 4}}{{x\left( {x - 2} \right)\left( {x + 2} \right)}}\\
= \dfrac{{{x^2} + 4x + 4}}{{x\left( {x - 2} \right)\left( {x + 2} \right)}}\\
= \dfrac{{{{\left( {x + 2} \right)}^2}}}{{x\left( {x - 2} \right)\left( {x + 2} \right)}}\\
= \dfrac{{x + 2}}{{x\left( {x - 2} \right)}}\\
o)\dfrac{{11x + 13}}{{3\left( {x - 1} \right)}} - \dfrac{{15x}}{{4\left( {x - 1} \right)}}\\
= \dfrac{{4\left( {11x + 13} \right) - 3.15x}}{{12\left( {x - 1} \right)}}\\
= \dfrac{{44x + 52 - 45x}}{{12\left( {x - 1} \right)}}\\
= \dfrac{{52 - x}}{{12\left( {x - 1} \right)}}\\
q)\dfrac{{2\left( {x - 2} \right)}}{{{{\left( {x - 2} \right)}^2}}} - \dfrac{{x + 2}}{{x\left( {x - 2} \right)}}\\
= \dfrac{2}{{x - 2}} - \dfrac{{x + 2}}{{x\left( {x - 2} \right)}}\\
= \dfrac{{2x - x - 2}}{{x\left( {x - 2} \right)}} = \dfrac{{x - 2}}{{x\left( {x - 2} \right)}} = \dfrac{1}{x}\\
s)\dfrac{{\left( {x + 2} \right)\left( {x + 1} \right) + 3\left( {x - 1} \right) - {x^2}}}{{\left( {x - 1} \right)\left( {x + 1} \right)}}\\
= \dfrac{{{x^2} + 3x + 2 + 3x - 3 - {x^2}}}{{\left( {x - 1} \right)\left( {x + 1} \right)}}\\
= \dfrac{{6x - 1}}{{\left( {x - 1} \right)\left( {x + 1} \right)}}\\
u)\dfrac{{4 - x + \left( {x - 2} \right)\left( {x + 2} \right) + 2x\left( {{x^2} - 2x + 4} \right)}}{{\left( {x + 2} \right)\left( {{x^2} - 2x + 4} \right)}}\\
= \dfrac{{4 - x + x - 4 + 2{x^3} - 4{x^2} + 8x}}{{\left( {x + 2} \right)\left( {{x^2} - 2x + 4} \right)}}\\
= \dfrac{{2{x^3} - 4{x^2} + 8x}}{{\left( {x + 2} \right)\left( {{x^2} - 2x + 4} \right)}}
\end{array}\)
Hãy giúp mọi người biết câu trả lời này thế nào?
Bảng tin