Question

What must be subtracted from $-12$ to get $-27$

Answer 1

Let $x$ be subtracted from $-12$ to get $-27$

So,

$$\begin{gathered} -12-x=-27 \\ \Rightarrow -12+27=x \\ \Rightarrow 15=x \end{gathered}$$

Therefore, $15$ must be subtracted from $-12$ to get $-27$