Whats the distance between (-9,-4) and (-9,5)

What is the slope of the equation y =

Tabby sells clothing at a retail store, and she earns a commission of 6.25% on all items she sells. last week she sold a pair of jeans for $32.50, a skirt for $18.95, and 2 blouses for $14.95 each. what was tabby's total commission? a $4.15 b $5.08 c $81.35 d $348.60

0if x and y vary inversely and y=6 as x=7, what is the constant of variation?