I really need help with -8 - 4(5m + 9)

(note i put the graph in so plz )the graph shows the amount of water that remains in a barrel after it begins to leak. the variable x represents the number of days that have passed since the barrel was filled, and y represents the number of gallons of water that remain in the barrel. what is the slope of the line

Will give brainliest if you answer question correct

The graph shows the distance kerri drives on a trip. what is kerri's speed . a. 25 b.75 c.60 d.50