The Associative Property of Addition states that the way numbers are grouped in an addition operation does not change their sum. This is expressed mathematically as:
\[ (a + b) + c = a + (b + c) \]
Looking at the options provided:
-
m⋅(x⋅y)=(m⋅x)⋅y
This represents the Associative Property of Multiplication. -
(x+y)+z+r=x+(y+z)+r
This correctly demonstrates the Associative Property of Addition. -
x⋅(y+z)=(x⋅y)+z
This does not represent the Associative Property (it's a mix of multiplication with addition). -
y−(x+1)=(y−x)+1
This does not demonstrate the Associative Property of Addition.
Therefore, the correct response is:
(x+y)+z+r=x+(y+z)+r