Question

what is the sum of -5 and -5?
○ 0
○ 10
○ -10

Explanation:

Step1: Recall addition of negative numbers

To find the sum of two negative numbers, we add their absolute values and keep the negative sign. The formula for adding two negative numbers \(a\) and \(b\) (where \(a<0\) and \(b<0\)) is \(a + b=-(|a| + |b|)\).
Here, \(a = - 5\) and \(b=-5\), so \(|a| = 5\) and \(|b| = 5\).

Step2: Calculate the sum

First, add the absolute values: \(| - 5|+| - 5|=5 + 5=10\).
Then, apply the negative sign: \(-5+(-5)=-(5 + 5)=-10\).

Answer:

-10 (the option with -10)