Question

2x^2 - 8

Answer 1

seems you still do not understand to work with variables.

Answer 2

it mixed factoring

Answer 3

yes but there is a variable x in this problem

Answer 4

ok how do you do it

Answer 5

take 2 common from both the operands 2x² and 8, you get
2( x² - 4 )
now there is a basic formula (a² -b²)= (a+b)(a-b)
2(x²-2²)
=2(x+2)(x-2)