## Precalculus (6th Edition)

There is no associative property for subtraction. To illustrate, if $a=1$ , $b=2$, and $c=3$, $(a-b)-c = (1-2)-3 = -1-3 = -1+(-3)=-4$ while $a-(b-c) = 1-(2-3) = 1 - (-1) = 1+1 = 2$ The two quantities are not equal.