Answer:
Larger number = 25
Smaller number = 14
Step 1. Establish variables and system of equations
Larger number = x
Smaller number = y
&
x + y = 39
y + 11 = x
Step 2. Isolate a variable in ONE equation
x + y = 39
y = 39 - x
Step 3. Substitute that into the OTHER equation to find x
y + 11 = x
(39 - x) + 11 = x
50 - x = x
50 = 2x
25 = x
Step 4. Substitute that into the OTHER equation to find y
x + y = 39
(25) + y = 39
y = 14
Hope this helps!