Write the following conjugate binomial in standard form.
like this example.

(a) (x + 3) (x - 3)
= x( x - 3) + 3 (x - 3)
= x^2 - 3x + 3x -9
= x^ 2 -9

i have to answer b like this but i'm not sure if you have to repeat (x+5) twice or (x-5) considering the fact that it's written like this instead.

b) (x - 5 ) ( x + 5)