Describe subtraction of rational numbers as adding

Question

the additive inverse, p - q = p +(-q).
Use the additive inverse to find -492.89-(-871.78).
Answer: 378.89
Describe this as a 7th Grader Simplified a lot so it can easily fit in a small text box

Answer 1

Subtraction of rational numbers can be thought of as adding the opposite (or additive inverse). For example, when you subtract \( q \) from \( p \) (written as \( p - q \)), you can change it to addition by using the opposite of \( q \) (which is \(-q\)). So, \( p - q = p + (-q) \).

Now, let's use this idea to solve \(-492.89 - (-871.78)\):

1. First, identify the additive inverse of \(-871.78\). The inverse is \(+871.78\).

2. Now rewrite the subtraction: \(-492.89 - (-871.78)\) becomes \(-492.89 + 871.78\).

3. Now, we just add:

   \(-492.89 + 871.78\) equals \(378.89\).

So the answer is \(378.89\).