Monday

September 22, 2014

September 22, 2014

Posted by **Jack** on Friday, October 12, 2007 at 6:31pm.

1) Where 2^x - 1 = y, is x or y the Mersenne prime?

2) I have noticed that in some cases, such as 27 * 3, I can break the problem up and arrive at the correct result:

27 * 3 = 81

(20 * 3) + (7 * 3) = 60 + 21 = 81

Does this work in all cases? I'm having trouble finding a problem that isn't correctly solved this way, but in the past I have tried this and arrived at the wrong answer. Does anyone know how this works?

- Math -
**bobpursley**, Friday, October 12, 2007 at 6:46pm2) it works in all cases.

(a+b)c=a*c + b*c is why this is true.

1) y is the Mersenne Prime. And, big news in that area, the first 44 are now known.

http://www.mersenne.org/

- Math -
**Jack**, Friday, October 12, 2007 at 7:52pmI see, thanks. I must have been doing it wrong when it didn't work.

**Answer this Question**

**Related Questions**

Science/ Social Studies - I need help with those two subjects. Please tell us ...

Business Communication - Which way of asking for action carries the highest ...

Math 8R - help!!!!!!!!!!!!! - Multi-Step Equations Solving Equations with ...

fractions - my teacher gave us some fraction problems for homework, but I'm ...

math - I appreciate all of your help. We had about 77 of these problems to do. ...

Math - I appreciate all of your help. We had about 77 of these problems to do. ...

cultural studies - world history - Hey. I have to write about Mayan and Aztec ...

ENGLISH - Help:Please change show me anthing that I need to do, by placing the ...

Geometry Proofs, HELP!! - I need help, I have a Geometry Exam on Monday. And I ...

English - Help:Please change show me anthing that I need to do, by placing the ...