Answer
Debra's mother is $2x-3$ years old.
Work Step by Step
In order to get from Debra's age, $x$, to her mother's age, we must first multiply by $2$, because the word "twice" is used. Then, we subtract $3$, because the words "$3$ less than" are used. This leads us to her mother's age, which is $2x-3$ years old.