Does a negative number times positive infinity equal negative infinity?
Yes. Multiplying a negative number by a very large positive number will equal a large negative number. If you have the function y = -x, then as x approaches infinity, y will approach negative infinity at the same rate.
X doesn't have to equal to 4, it can be equal to any real number really (as in, not i), the really important part is that Y is equal to both Positive and Negative Infinity, just like in a horizontal line Y can be equal to any real number, but, in this case, X has to be equal to both Positive and Negative Infinity.
Why does a positive number divided by a negative number equal a negative number instead of infinity?
If you think about it, the division simbol means how many times a number can go into another number, so a positive number, like 5 goes into a negative number, like -25, -5 times, because the -5 is less than 1, and 5 cant go into anything less than one even once, so it goes in a negative amount of times. I'm not sure why a positive number divided by a negative number would be…