pls help hurry man cmon

Answer:
associative property of addition.
In step 3:
1 + 19
20
Here we will add the integers, so division and multiplication eliminated.
Indicate which property is illustrated in step 3?
[tex] \rm \: Step \: 3 \asymp > 1 + 19[/tex]
This property states that when performing addition, how numbers are grouped will not change the resulting sum...~