Question:
What number should be subtracted from $\frac{-3}{4}$ to get $\frac{-1}{2} ?$
Solution:
Let the required number be $x$.
Thus, we have :
$\frac{-3}{4}-x=\frac{-1}{2}$
$\Rightarrow \frac{-3}{4}+\frac{1}{2}=x$
$\Rightarrow x=\frac{2-3}{4}$
$\Rightarrow x=\frac{-1}{4}$