Does $$x=7$$?
>(1) $$6 \lt x \lt 8$$
>(2) $$x \lt 9$$

Incorrect.
Did you consider that $$x$$ may be a non-integer?

Incorrect.
The variable $$x$$ may have any value smaller than 9. Maybe it's 7 and maybe it's not.

Incorrect.
Combining both statements does not yield additional data regarding $$x$$.

Incorrect.

Correct.
Statement (1) puts $$x$$ between 6 and 8, and so $$x$$ may be 7, but also it may not. So **(1) Maybe → Insufficient → BCE**.
According to Statement (2), $$x$$ may have any value smaller than 9, so **(2) Maybe → Insufficient → CE**.
Combining both statements does not add to the data given regarding $$x$$, so **(1)+(2) Maybe → Insufficient → E**.
Choosing E in Data Sufficiency is perceptually uncomfortable. But bear in mind that Answer E is correct in approximately 20% of all Data Sufficiency questions.

Statement (1) ALONE is sufficient, but Statement (2) alone is not sufficient to answer the question asked.

Statement (2) ALONE is sufficient, but Statement (1) alone is not sufficient to answer the question asked.

BOTH Statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient to answer the question asked.

EACH statement ALONE is sufficient to answer the question asked.

Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.