Giải các phương trình sau 1. 12x + 1/11x – 4 + 10x -4/9 = 20x + 17/18 20/10/2021 Bởi Aaliyah Giải các phương trình sau 1. 12x + 1/11x – 4 + 10x -4/9 = 20x + 17/18
Đáp án: $\begin{array}{l}Dkxd:x \ne \dfrac{4}{{11}}\\\dfrac{{12x + 1}}{{11x – 4}} + \dfrac{{10x – 4}}{9} = \dfrac{{20x + 17}}{{18}}\\ \Rightarrow \dfrac{{18.\left( {12x + 1} \right) + 2.\left( {10x – 4} \right).\left( {11x – 4} \right)}}{{18\left( {11x – 4} \right)}}\\ = \dfrac{{\left( {20x + 17} \right)\left( {11x – 4} \right)}}{{18\left( {11x – 4} \right)}}\\ \Rightarrow 216x + 18 + 2.\left( {110{x^2} – 84x + 16} \right)\\ = 220{x^2} – 80x + 187x – 68\\ \Rightarrow 216x + 18 + 220{x^2} – 168x + 32\\ = 220{x^2} + 107x – 68\\ \Rightarrow 59x = 118\\ \Rightarrow x = 2\left( {tmdk} \right)\\Vậy\,x = 2\end{array}$ Bình luận
Đáp án:
$\begin{array}{l}
Dkxd:x \ne \dfrac{4}{{11}}\\
\dfrac{{12x + 1}}{{11x – 4}} + \dfrac{{10x – 4}}{9} = \dfrac{{20x + 17}}{{18}}\\
\Rightarrow \dfrac{{18.\left( {12x + 1} \right) + 2.\left( {10x – 4} \right).\left( {11x – 4} \right)}}{{18\left( {11x – 4} \right)}}\\
= \dfrac{{\left( {20x + 17} \right)\left( {11x – 4} \right)}}{{18\left( {11x – 4} \right)}}\\
\Rightarrow 216x + 18 + 2.\left( {110{x^2} – 84x + 16} \right)\\
= 220{x^2} – 80x + 187x – 68\\
\Rightarrow 216x + 18 + 220{x^2} – 168x + 32\\
= 220{x^2} + 107x – 68\\
\Rightarrow 59x = 118\\
\Rightarrow x = 2\left( {tmdk} \right)\\
Vậy\,x = 2
\end{array}$