using 9 odd numbers the total should be 90

Answer 1

((3*3*15/3)+21/7)*3 + 55 -1

Answer 2

How about 9 odd numbers, all of which are the number 9!

(9 + 9 + 9) - (9 + 9 + 9) + 9 * 9 + 9 = 90