The product of the slopes of perpendicular lines (excluding vertical lines) always equals -1. true or false

This is true.  The slope of the perpendicular line is equal to the negative reciprocal.  This means that you "flip" the fraction and multiply by negative 1.  Since the reciprocal is also the multiplicative inverse (something you multiply by a number to get 1), and the signs are different (one is positive, one is negative) it equals -1.

Hope this helps!

what is all that apply?

the answer is d

the answer is in the first quadrant, which make the y-int positive.

since the dots are going down, therefore the correlation is negative

i hope it is right.