I need some help. How did they find the slope of the demand curve and the slope of the supply curve in Market A? (The answer is already provided in the image. I just need help how did they get the answer.)

S S Price Price $10 $10 CS CS $9 $8 PS Trans DVL D Cost D $5 $5 $4 PS $1 $1 1 5 10 Quantity 5 10 Quantity 1. On the graph for Market A, what is the slope of the demand curve? -0.4 2. On the graph for Market A, what is the slope of the supply curve? +2