How come 1- (-2) is positive 3
But -2 -1 is Negative 3
???
2007-02-25 02:34:24 · 7 answers · asked by Pretty 1 in Education & Reference ➔ Homework Help
Because if you're subtracting a negative number, you are actually adding it as a positive number (two negatives make a positive), and if you're subtracting a positive number from a negative number, you're actually adding it as a negative number (since the act of subtracting it makes it negative).
Thus, 1 - (-2) is the same as 1 plus 2,
and -2 - 1 is the same as -2 plus -1.
2007-02-25 02:41:00 · answer #1 · answered by Bad Kitty! 7 · 0⤊ 0⤋
There is no subtraction of integers. It is the addition of opposites. So,1-(-2)= keep the first term 1, change subtraction to addition + and take the opposite of -2 which is +2. Put it together and you get 1 + 2 = 3. In the 2nd case, keep the -2, change subtraction to addition and take the opposite of 1 which is -1.So, -2 + -1 = -3
Point of information......a negative plus a negative is a negative but a negative times a negative is a positive.
2007-02-25 03:50:20 · answer #2 · answered by dpirsq2 5 · 0⤊ 0⤋
in the first equation, the two negative signs cancel each other out -- its the same as equating 1+2. It is a multiplication principle. this is how you get 3
In the second, you're negating one more unit from your already negative 2.. Like if you borrow $2 from your Mom, then another $1 a day later--- you then owe your mother $3. Addition/Subtracting negative #'s do have have the same principles as multiplying/dividing -/+ #'s
2007-02-25 02:46:50 · answer #3 · answered by Anonymous · 0⤊ 0⤋
If you subtract a negative, it turns the double negatives into a positive (or plus function). Whereas, if you subtract from an existing negative number, you are not creating the double negative.
2007-02-25 02:37:05 · answer #4 · answered by Kerry 7 · 0⤊ 0⤋
the first answer is positive because a minus and a minus together is a positive so you dont take the numbers away and add the numbers instead.
Whereas the 2nd one there are not two minus numbers together, you only have -2, which is taking away 1 so it still equals a minus figure.
Remember
a minus and a minus = +
a minus and a positive = -
2007-02-25 02:40:50 · answer #5 · answered by Honey!! 5 · 0⤊ 0⤋
Mt respond would be something cheesy like: a million-2 What you gonnna do? 3-4 you comprehend what Freddy has in shop 5-6 you will nonetheless take some licks. 7-8 For you comprehend he loves killing all you reformatory bate. 9-10 once you do you would be in freddy's den! =p
2016-10-16 11:07:31 · answer #6 · answered by olis 4 · 0⤊ 0⤋
just cause 2 negatives always makes a positive! dont know why thats just the way it is....
sorry i couldnt be of more help! Never question the mathematical system!
2007-02-25 02:38:08 · answer #7 · answered by woohooo 4 · 0⤊ 0⤋