#1

ok i know why(-)(+)=- and why (+)(+)= + but......why is a negative number times a negative number positive?

#2

Just because.

#3

The second negative cancels out the first. "I don't not want to do something" = "I want to do something"

#4

I wouldn't question it. Doing so would cause the bomb they planted in your bladder to explode.

#5

If we can agree that a negative number is just a positive number multiplied by -1, then we can always write the product of two negative numbers this way:

(-a)(-b) = (-1)(a)(-1)(b) = (-1)(-1)ab

For example,

-2 * -3 = (-1)(2)(-1)(3)

= (-1)(-1)(2)(3)

= (-1)(-1) * 6

So the real question is,

(-1)(-1) = ?

and the answer is that the following convention has been adopted:

(-1)(-1) = +1

This convention has been adopted for the simple reason that any other convention would cause something to break.

For example, if we adopted the convention that (-1)(-1) = -1, the distributive property of multiplication wouldn't work for negative numbers:

(-1)(1 + -1) = (-1)(1) + (-1)(-1)

(-1)(0) = -1 + -1

0 = -2

Since everything except +1 can be excluded as impossible, it follows that, however improbable it seems, (-1)(-1) = +1.

Yay for elementary.

(-a)(-b) = (-1)(a)(-1)(b) = (-1)(-1)ab

For example,

-2 * -3 = (-1)(2)(-1)(3)

= (-1)(-1)(2)(3)

= (-1)(-1) * 6

So the real question is,

(-1)(-1) = ?

and the answer is that the following convention has been adopted:

(-1)(-1) = +1

This convention has been adopted for the simple reason that any other convention would cause something to break.

For example, if we adopted the convention that (-1)(-1) = -1, the distributive property of multiplication wouldn't work for negative numbers:

(-1)(1 + -1) = (-1)(1) + (-1)(-1)

(-1)(0) = -1 + -1

0 = -2

Since everything except +1 can be excluded as impossible, it follows that, however improbable it seems, (-1)(-1) = +1.

Yay for elementary.

#6

(+)(+)

Anybody? No?

*leaves thread*

#7

because the guys who started mathematics said so.

#8

#9

They cancel each other out. When you multiply two negatives, you're effectively canceling out a negative, and since the number can't be 0 it must be a positive number.

This is one of those things where you're better off just believing that this is just how it is and not questioning it, because it's hard to thoroughly understand and even harder to explain.

This is one of those things where you're better off just believing that this is just how it is and not questioning it, because it's hard to thoroughly understand and even harder to explain.

#10

Because ( . Y . )

#11

a negative number times a positive number equals a negative number cuz of (3)(-3)

-3

-3

-9

a negative has a more complicated reason, if you multiply the reciprocal(?) it gives you a positive number, example=

1

is the same as

3

Which also is the same as

-3

so, if the negative is converted into the positive with the reciprocal (sp?) your really just multiplying it by 2 postives

-3

-3

__-3__-9

a negative has a more complicated reason, if you multiply the reciprocal(?) it gives you a positive number, example=

__-3__1

is the same as

__1__3

Which also is the same as

__-1__-3

so, if the negative is converted into the positive with the reciprocal (sp?) your really just multiplying it by 2 postives

#12

BECAUSE IT IS DAMMIT!

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

Don't rock the boat

#13

grow a brain and think about it

#14

Because you have negative negatives. And what is the negative of a negative? positive.

#15

I cum blood.

#16

Its basicly a root off of finding the absolute value.

#17

Because math is garbage.

#18

Aww, I wanted to answer this one.

think of it as a math-line.

negatives - 0 - positives

think of it as a math-line.

negatives - 0 - positives

#19

Aww, I wanted to answer this one.

think of it as a math-line.

negatives - 0 - positives

Damnit seth everytime you make a post i see your avatar and get sad about my pokemon red being lostedid .

I was going to post the gridline but i gots lazy.

#20

Because mathematicians decided they'd make up random formulas for numbers to torture humanity for the rest of its existence.