Do you need a comma before the word

Depends what the context is, but usually yes, but just to make sure, send me the sentence, and the context.

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4

femininity is conveyed through bernice's personality. she doesn't act how the other girls act and everyone thinks she is weird. she learns how to act in a way that was considered femininely appropriate at the time. she becomes so popular but her attempts to be liked end up backfiring when she is pressured into bobbing her hair. the author wrote that bernice cut off her cousin's hair in revenge for tricking her to cut her hair. this was the authors way of trying to change the way feminine is defined and the way women are expected to act.