Sorry to be pedantic, but a 9th chord actually has a 9th and a _flat_ 7th. For example C9 has the notes C-E-G-Bb-D. 9th chords are part of the dominant group, not the major group.
A chord with a 9th and a 7th is a _major_ 9th. For example, the chord C-E-G-B-D is Cmaj9 (sometimes written C triangle 9).
A chord with a 9th and a 7th is a _major_ 9th. For example, the chord C-E-G-B-D is Cmaj9 (sometimes written C triangle 9).