Question

Why is -2x -8 an algebraic expression

Answer 1

Because algebra means finding the unknown
it is usually used in real life
for example if if 1/2 of the legnth of a line is 8 then what is the legnth
so then 1/2 x=8 and that is algebraic
since it has x, or an unknown in it, it is an algebraic expression

Answer 2

Because it contains an un-known variable denoted as X