when you have two log with same base which are adding to each other you can say:
log(base 8)(2 * 4x^2) = 1
so u multiplied them to each other:
log(base 8)(8x ^2) = 1 ⇒ so now you can say:
8^1 = 8x ^2 ⇒ 8 = 8x^2 ⇒ 1 = x^2 ⇒ x =1 :)))
i hope this is helpful
have a nice day