It is 70 because common sense people
Hey there!
The answer to your question is 
Given:

First, we distribute the negative sign to both terms (
) This would make the
negative and the
positive, so we have:

Add them together and we get:

Have a nice day!
-8/5 is a rational number because in order to be a rational number it must be able to be written as a fraction. -8/5 is a fraction; therefore, the negative does not affect it.