Answer:
the critical points are (0,0) , (0, 20), (12, 0) , (4,16)
Step-by-step explanation:
To consider the autonomous system


The critical points of the above system can be derived by replacing x' = o and y' = 0.
i.e.


x = 0 or 24 - 2x - y = 0 ----- (1)
Also

y( 20 -y - x) = 0
y = 0 or 20 - y - x = 0 ----- (2)
By solving (1) and (2);
we get x = 4 and y = 16
Suppose x = 0 from (2)
y = 20
Also;
if y = 0 from (1)
x = 12
Thus, the critical points are (0,0) , (0, 20), (12, 0) , (4,16)