Saturday

January 31, 2015

January 31, 2015

Posted by **Shay** on Thursday, August 2, 2012 at 11:32am.

a=6,m=21,b=15 d=gcd(6,21)=3 solns.

6x=15(mod 21) 2x=5(mod 7)

21=6(3)+3

6+3(2)+0

0=6-6

6-(21-6(3))=3

6-21+18=3

6( )-21()=3

(21-6(3))(15)-6=3 ???????

- Math -
**Steve**, Thursday, August 2, 2012 at 4:29pm6x = 21y + 15 for some y.

or,

2x = 7y + 5

since 2x is even, y must be odd.

y x

1 6

3 13

5 20

7 27

. . .

any number x of the form 2x = 7(2k+1)+5 is a solution, since

2x = 14k+7+5 = 14k+12

6x = 42k + 36

and 36 = 15 mod 21

**Answer this Question**

**Related Questions**

math - Which two is true as i'm confused A) 3+7 10 mod 15 17 + 9 4 mod 21 ...

Math - Which Statements of congruence are true and which are false and why? 177 ...

math - Which Statements of congruence are true and which are false and why? 177 ...

Math - Which Statements of congruence are true and which are false and why? 177 ...

math - how do we find the least residue of 1789 (mod 4), (mod 10), (mod 101)

math - how do we find the least residue of 1789 (mod 4), (mod 10), (mod 101)

probability - how do we find the least residue of 1789 (mod 4), (mod 10), (mod ...

another college math question - Please teach me. I am completely blank with it...

Math (Proof) - Prove that if ab = ac (mod n) and a is relatively prime to n, ...

Discrete Math - Let a, b, c, and d be integers, and let n be a positive integer...