Answer:
0, 130, -1.5
Explanation:
Lets go over a few things that will help answer the questions:
A + and - make a - sign
A - and a - make a + sign
Ok, now lets sum our first expression:
56+(-56)
Remembering above that a + and - make a - sign:
56-(56)
=
0
Next:
(-240)+370
This is just a postive adding to a negative. So its:
-240+370=130
Finally we have:
(-5.7)-(-4.2)
This may look a bit confusing, so lets clean it up a bit:
The parethese around the -5.7 dont matter, and can be removed:
-5.7-(-4.2)
And remembering that a - and - make a +:
-5.7+4.2
Now adding the postive to the negative value:
-1.5
It is still a negative because the postive value being added to to -5.7 was smaller, so it still was negative, just a smaller negative number.
Hope this helps!