Đáp án:
$\text{ a)$\dfrac{1}{4}$ - $\dfrac{3}{2}$ + $\dfrac{1}{5}$ . $\dfrac{12}{5}$ }$
$\text{= $\dfrac{1}{4}$ - $\dfrac{3}{2}$ + $\dfrac{12}{25}$ }$
$\text{= $\dfrac{50}{200}$ - $\dfrac{300}{200}$ + $\dfrac{96}{200}$ }$
$\text{= $\dfrac{-154}{200}$ }$
$\text{= $\dfrac{-77}{100}$ }$