math problem?

Question

What does -1 minus 2 equal. Also how do you add negative and postive numbers? Any help would be great!

Answer 1

-3

Answer 2

Subtraction is the same as adding a negative number.

If both numbers are negative or positive then you add them.
Two positives will add to give you a neagative
1+2=3

Two negatives will add to give you a negative
-1-2=-3 (same as -1+-2=-3)

When one number is positive and one number is negative then you subtract the numbers. And then the answer has the same sign as the larger number when ignoring the signs (most math textbooks will use the technical term absolute value)

Examples

-3 + 2 = -1 (3 - 2 = 1 and then ignoring the signs 3 is larger and it is negative so the answer is negative)

-2 + 3 = 1 (again 3 - 2 = 1 but this time the larger number ignoring the signs is positive so the answer is positive)

Answer 3

-1 - 2 = -3.

Adding a negative number to a positive number is essentially subtraction. Same goes for adding a positive number to a negative number.

For example:

-3 + 1 = -2

-1 + 3 = 2

Essentially, it's subtraction, and the core of subtraction is finding the _difference_ between the two numbers involved in the subtraction problem.

Answer 4

-1 - 2 = - 3

To add negative and positive numbers, normally add them, and retain the sign of the bigger number
Ex.
a) -2 + 5 = 3
-2 + 5 ==> 5 + (-2) = 3
b) 4 - 12 = -8
4 - 12 ==> 4 + (-12) = 8 or
-12 + 4 = -8
To add negative numbers, add them and retain the negative sign
Example
a) -12 - 8 ==> -12 + (-8) = -20
b) (-20) + (-25) ==> -20 - 25 = -45

In adding numbers with negative and postive numbers, THINK of the NUMBER LINE.