Question

Factor Completely: 2x2 − 18

Prime

2(x2 − 9)

2(x + 3)(x − 3)

2(x + 3)(x + 3)

Answer 1

take 2 common then
2(x^2-9)
or
2(x^2-3^2)
now use
\[\Large a^2-b^2=(a+b)(a-b)\]

Answer 2

I don't know

Answer 3

Let me give you an Example
if you have
\[\Large (x^2-4^2)\]
then use the following formula to factor it
\[\Large a^2-b^2=(a+b)(a-b)\]
it becomes
\[\Large x^2-4^2=(x+4)(x-4)\]

can you factor now \[\Large (x^2-3^2)\] ??