Question

Choose the correct answer and Fill in the blanks:

$\left(-9\right)+\_\_\_=\left(-1\right).\left[\left(+8\right)/\left(-8\right)\right]$

Answer 1

If we substitute $+8$ we get

$$\begin{gathered} \left(-9\right)+\left(+8\right) \\ -9+8 \\ =-1 \end{gathered}$$

Hence, $\left(-9\right)+\left(+8\right)=-1$