A nonzero product has 25 factors, 16 of which are negative. What is the sign of the products ? Explain

Question

ipwnbunnies · Answer

16 negative factors. That means 25 - 16 = 9 factors are positive.
Let's get rid of all the positive factors.
If we multiplied each of the 9 positive factors by 9 negative factors, you should end up with a negative number. There are an odd amount of negative numbers being multiplied.

We used up 18 factors, all 9 positive factors included. Now, we're left with 25 - 18 = 7 negative factors.

We have our current negative numbers. If we multiplied 7 negative numbers, we'll get a positive number.

anonymous · Answer

So I  can use that @iPwnBunnies

ipwnbunnies · Answer

Yeah, I suppose.

anonymous · Answer

Alright. @iPwnBunnies 

What number must be subtracted from -12 to obtain 24 ? 
36 
What number must be subtracted from -20 to obtain 15 ? 
35

Is this right or wrong ?

anonymous · Answer

@iPwnBunnies

ipwnbunnies · Answer

It says subtracted from -12....hmm
-12 - x = 24?  That's how I see it in words. I'm not too sure though.

anonymous · Answer

So you don't know or you not sure @iPwnBunnies