Let x = $20 bills
Let y = $50 bills
x + y = 13
20x + 50y = 410
Solve for x in first equation and then substitute into second equation:
x= 13 -y
20 (13 - y) + 50y =410
now solve the equation:
260 - 20y +50y= 410
30y = 150
y=5
Now, plug this bag into either equation, I will use the first one: x + y =13
x + 5 = 13
x=8
check your answer: 8 x $20 = 160
5 x $50 = 250
Checks out perfect. there is your answer!!! 8 $20 bills and 5 $50 bills
