What percent is represented by the shaded area khan academy

(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

One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)

    choose the correct definition for  extremo.  a.  end      b.  extra      c.  extract      d.  eventual