Solve the following congruence equations
(a) 12x º 21(mod8) ; (b) 7x º 16(mod13) .
congruences
2010-11-20 8:53 pm
回答 (2)
2010-11-20 11:06 pm
✔ 最佳答案
(a)12x ≡ 21 (mod 8)
2*12x ≡ 2*21 (mod 8)
24x ≡ 42 (mod 8)
0*x ≡ 42 (mod 8)
0 ≡ 42 (mod 8), impossible.
No solution.Or
12x - 21 = 8p for some integer p
21 = 12x - 8p = 4(3x - 2p), impossible.
No solution.
(b)
7x ≡ 16 (mod 13)
2*7x ≡ 2*16 (mod 13)
14x ≡ 32 (mod 13)
x ≡ 6 (mod 13)
2010-11-20 9:56 pm
what is 12x? 12 multiplies x or 120 + x?
what is 7x? 7 multiplies x or 70 + x?
what is 7x? 7 multiplies x or 70 + x?
收錄日期: 2021-04-23 23:26:00
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