Answer:
- 4 + (-5) = - 9
Step-by-step explanation:
In the number line when we move x units to the right-hand side, then this means +x movement and moving x units to the left-hand side, then this means -x movement.
Now, in our case it is asked how many units must be added to - 4 to get - 9.
Since -9 is to the left of -4 on the number line, therefore, we have to move by 5 units to the left-hand side i.e. -5 movement.
Therefore, - 4 + (-5) = - 9
⇒ - 4 - 5 = - 9 (Answer)
