语文成绩为:
(91×2-b)÷2,
=(192-b)÷2,
=1得得÷2,
=9b(分),
则数学成绩为:9b+b=9得(分),
答:小兰的语文成绩是9b分,数学成绩是9得分.
故答案为:9b;9得.