Answer:
y = 8 is the smaller number.
Explanation:
Sove the system by adding the two equations together, one on top of the other. Add from the top, down.
x + y = 20
x - y = 4
________
2x = 24
Divide by 2.
x = 12
Put this back into either original equation.
x + y = 20
12 + y = 20
Subtract 12.
y = 8
The numbers are 12 and 8.
8 is the smaller number.