Biết: 3x/2×5+3x/5×8+3x/8×11+3x/11×14=1/2 Tìm x

Đáp án:

Giải thích các bước giải:

\(\begin{array}{l}
\frac{{3x}}{2}.5 + \frac{{3x}}{5}.8 + \frac{{3x}}{8}.11 + \frac{{3x}}{{11}}.14 = \frac{1}{2}\\
 \Leftrightarrow \frac{{15x}}{2} + \frac{{24x}}{5} + \frac{{33x}}{8} + \frac{{42x}}{{11}} = \frac{1}{2}\\
 \Leftrightarrow \left( {\frac{{15}}{2} + \frac{{24}}{5} + \frac{{33}}{8} + \frac{{42}}{{11}}} \right)x = \frac{1}{2}\\
 \Leftrightarrow \frac{{8907x}}{{440}} = \frac{1}{2} \Leftrightarrow x = \frac{1}{{84}}
\end{array}\)