You go down 9 floors in an elevator. How would you write the integer?

-9

Step-by-step explanation:

Going down= negative

u write negative 9

Step-by-step explanation:

for finding the midpoint of any given 2 pair of points simply add the respective x coordinates with other x coordinate and the y coordinate with other y coordinate and divide them by 2

in your question it will be :

(3+1)/2 for the x coordinate of mid point i.e 2

[8+(-4)]/2 for the y coordinate of midpoint i.e 2

so coordinates of mid point of points (3,8) and (1,-4) will be (2,2)

use this formula:

p(a\b) = p(a and b)/p(b).

take it from here.