what does the X mean in algebra

3 answers

A) X=5
B) X=9
C) X=1
D) X=5
E) X=8
x usually represents an unknown quantity

eg ... x + 3 = 5 ... x would be 2
I Think X is a letter that is used in algebra/Math, for example,

X=4/4
X=35/6
Y=3x+4