Đáp án:
\[ - \frac{1}{{20}}\]
Giải thích các bước giải:
\(\begin{array}{l}
25\% - \frac{3}{2} + 0,5 \times \frac{{12}}{5}\\
= \frac{{25}}{{100}} - \frac{3}{2} + \frac{5}{{10}} \times \frac{{12}}{5}\\
= \frac{1}{4} - \frac{3}{2} + \frac{1}{2} \times \frac{{12}}{5}\\
= \frac{1}{4} - \frac{3}{2} + \frac{6}{5}\\
= \frac{5}{{20}} - \frac{{30}}{{20}} + \frac{{24}}{{20}}\\
= - \frac{1}{{20}}
\end{array}\)
