ANSWER
Commutative property of addition.
EXPLANATION
Let a,b be real numbers. The commutative property of addition states that,
[tex]a + b = b + a[/tex]
If we let a=-10 and b=6, then
[tex]-10+6=6+(-10)[/tex]
Therefore the given expression demonstrates the commutative property of addition.
The commutative property of addition tells us that, the order in which we add two real numbers does not affect the result.