Is the difference between two negative numbers numbers is always negative.

Yes. Think of it like this. You borrowed $1 from your friend for a candy bar. You now have -$1 because you owe your friend money. If you ask your friend for another $5 because you found another thing you wanted you have -$6. When you already have a negative, you are subtracting even more from that, which brings you to an even higher negative number

Y= -2x-1 the negative in front of the 2 is because the slope is negative and the -1 is because it’s down 1 on the y axis.

Ithink the versus years?