Answer
true
Work Step by Step
RECALL:
The Addition Property of Inequality states that if $a \lt b$, then $a+c \lt b+c$.
The given inequality can be written as:
$a+(-c) \lt b+ (-c)$
Thus, using the Addition Property of Inequality, if $a \lt b$, then $a+(-c) \lt b+(-c)$.
Therefore, the given statement is true.