What's the rule for subtracting signed numbers?

Question

i forgot what it was like the rule for adding signed numbers is subtract small number from big number and keep the big numbers sign, well what about subtracting sigend numbers?

example: (-5) - 3 = ?

Answer 1

If you are subtracting with negatives (ie. (-5)) you would add the opposite.

So it would be,

(-5) + (-3)= -8 (negative eight)

Answer 2

Think of two yardsticks being put start of one to start of other (zero point on both together and the 36" point being farthest apart). That is the concept of a number line. When you go to the right on a yardstick from any starting point you are going more positive. When you go to the left you are going more negative.

In your example you are already 5" from the points where both zeroes are together. That location is -5. Then you need to go another 3" to the left. That sends you further left from -5 so you are down at -8. Try the same thing with some other numbers and you will see it is easy to get the trick to it.

Answer 3

You have -5 and you're subtracting another 3 from it, so the answer is -8. It helps sometimes if you think of the number line.

Answer 4

The rule is:
+(-) = -
-(+) = -
+(+) = +
-(-) = +

So (-5)-3=-8

Answer 5

(+) + (+) = (+)
(-) - (+) = (-) + (-) = (-sum)
(+) - (+) = (+) + (-) = (+difference) [if the 1st no. > the 2nd no.]
(+) - (+) = (+) + (-) = (-difference) [if the 2nd no. > 1st no.]
(-) - (-) = (-) + (+) = (-difference) [if the 1st no. > the 2nd no.]
(-) - (-) = (-) + (+) = (+difference) [if the 2nd no. > the 1st no.]

e.g:
(-5) - 3
(-) - (+) = (-) + (-) = (-sum)
so...
-5 - 3 = -8

Answer 6

a -- b = a -- b
a -- (--b) = a + b
-- a -- b = -- (a + b)
-- a -- (--b) = -- a + b = b -- a if b > a,
= -- (a -- b) if a > b