Question

Which property justifies the following steps:
Step 1 : 1/7x-6/3+13/7x=5
Step 2 : 1/7x+13/7x-6/3=5

Answer 1

Step 3:
14/7x-6/3=5
2x-2=5
2x=5+2
2x=7
x=7/2

Answer 2

Commutative.

Hope this helps :)