моя російська і українська змішані.
:)
Language - мова - is a feminine noun, that's why we use моя, російська, українська.
-а and -я are always the endings for feminine adjectives and possesive pronouns.
Note also that in Ukrainian the verb to be - є - is almost always omitted.
My Russian and Ukrainian are mixed.
мій моя російськийа і українськийа є змішаними (the word "language (мова)" has a female gender in Ukrainian.