nandip said:
-10-3+5
ok this is how i do it but i need to kno if its right:
3+5=8
-10-8=-2
Your approach would have been correct, if the given expression were to have associated the 3 and 5 with grouping symbols, like this:
-10 - (3 + 5)
But it didn't.
So, there's two ways of looking at the expression -10 - 3 + 5.
Following the Order of Operations, we would do the subtractions and additions AS THEY OCCUR, moving from left to right.
In other words, start with -10 minus 3, and then add 5 to the result. You'll get -8.
The other viewpoint is to see subtraction as an "abbreviation" of adding signed numbers.
In other words, you have three numbers being ADDED together: negative ten, negative three, and positive 5.
(-10) + (-3) + (5)
The Commutative Property says that we can add numbers in any order we like.
So we could add -3 and 5 first. 5 - 3 = 2
Now add -10 to the result.
-10 + 2 = -8
I strongly suggest that you begin by using the Order of Operations. You need that foundation.