Base 9 Mathematics

Post a math problem, and the next person tries best to answer it. If there is a problem before that was not solved yet, you can try that one too. When you post a problem, include its answer in spoilers so people can double-check.

The catch? It's base 9*.

Both the question and the respective answer should be in the same base. That means if above person posts 25 + 36, that means 23 + 33 = 56, so you write 62 in base 9.

This doesn't have to be repetitive arithmetic thread. If you have a problem involving trigonometry or complex variables you can post that too, although that might cause more confusion for the next person.

<Update> When you ask a question, post its answer in spoiler so people can double-check.

• 5 + 4 = ? 10

edited 17th Jun '11 11:17:50 PM by abstractematics

10 in base (9).

6 * 9 in base 13?

42.

7 * 20, base 9.

112

(also, no link to Hitchhiker's Guide to the Galaxy's article? I am disappoint, that's why I chose THAT particular one!)

((9) x 10(9)) x (9) (is superscript and subscript possible? becuase that seocnd 9's meant to be one of those.) in base 10.

EDIT beaten

edited 17th Jun '11 2:53:19 PM by Hatshepsut

Wait, 9 * 10^9 * 9 in base 10? That's 8.1 * 10^10. I don't understand the question.

8 * 12 = ? 107

Assume base 9 if not specified.

107.

1+13310!*

You seriously expect me to take 9000 factorial*

x^2 + 7x + 11 = 0, find x. -2, -5

My bad, I mixed things up there.

edited 18th Jun '11 9:11:17 AM by abstractematics