Respuesta :
Explanation
First of, you should know that integers are whole numbers.
There are positive integers (positive whole numbers, that is, normal whole numbers greater than 0, for example, 7, 98, 14 etc.) and there are negative integers (negative whole numbers, that is, whole numbers less than 0, for example, -3, -37, -101 etc.)
So, the first tip about adding and subtracting these numbers is to look at them in monetary terms.
Always look at positive numbers like money you have in your pockets (cash at hand).
And look at negative numbers like money you're owing someone.
So, we can then go through the different types of addition and subtraction of integers now.
- Addition of two positive numbers
** 2 + 2
You can interprete this simple addition as having $2 and another $2 is given to you, this means you've got $4 now.
2 + 2 = 4
** 17 + 7
You can interprete this simple addition as having $17 and another $7 is given to you, this means you've got $24 now.
17 + 7 = 24
- Subtraction of two positive integers
** 7 - 3
Look at this like having $7, then -3 means $3 is taken away from it, then you've got only $4 left.
7 - 3 = 4
** -15 + 10
This means you're owing $15, and you've got only $10, after paying the $10, there's still a debt of $5 left. So,
-15 + 10 = -5
Before the next two further types of adding/subtracting integers, weneed to also note the following
(+) × (+) = (+)
(+) × (-) = (-)
(-) × (+) = (-)
(-) × (-) = (+)
These helps us to simplify these additions and subtractions that involve a mix of positve numbers and negative numbers or just strictly working with negative numbers.
Addition of two negative numbers
** -5 + (-3)
Normally, with the former approach, this just means a debt of $5 is added to a debt of $3, these come together to give a bigger debt of $8.
But we can simplify the given equation further because we know that
(+) × (-) = (-), So,
-5 + (-3) = -5 - 3 (The plus sign before the -3 and the minus sign in the bracket multiply to give a negative/minus sign).
So,
-5 + (-3) = -5 -3 = -8
** -7 + (-4)
-7 + (-4) = -7 - 4 = -11
Subtraction of two negative integers
** -5 - (-5)
Recall that
(-) × (-) = (+), So,
-5 - (-5) = -5 + 5
Which then translates to owing $
