Loading [MathJax]/jax/output/SVG/jax.js
 
+0  
 
0
3594
1
avatar+1836 

(A)  Find a number $0\leq x<14$ that solves the congruence $9x \equiv 9 \pmod{14}$.

(b)  Find a number $0\leq x<5$ that solves the congruence $3x \equiv 4 \pmod{5}$.

(c)  Find a number $0\leq x<1000$ that solves the congruence $999x \equiv 998 \pmod{1000}$.

(d)  Find a number $0\leq x<21$ that solves the congruence $4x \equiv 17 \pmod{21}$.

 Jul 30, 2015

Best Answer 

 #1
avatar+26396 
+5

$(A)$Find a number $0x<14$thatsolvesthecongruence$9x9(mod14)$.$(B)$Find a number $0x<5$thatsolvesthecongruence$3x4(mod5)$.$(C)$Find a number $0x<1000$thatsolvesthecongruence$999x998(mod1000)$.$(D)$Find a number $0x<21$thatsolvesthecongruence$4x17(mod21)$.

 

\left\{ \begin{array}{l} $(A)$\\ $(B)$\\ $(C)$\\ $(D)$ \end{array} \right\}= \left\{ \begin{array}{lcr} x&=&1\\ x&=&3\\ x&=&2\\ x&=&20 \end{array} \right\}, \small{\text{ because } \left\{ \begin{array}{lcr} 9\cdot 1 &\equiv& 9 \pmod{14}\\ 3\cdot 3 &\equiv& 4 \pmod{5}\\ 999\cdot 2 &\equiv& 998 \pmod{1000}\\ 4\cdot 20 &\equiv& 17 \pmod{21}\\ \end{array} \right\}

 

.
 Jul 31, 2015
 #1
avatar+26396 
+5
Best Answer

$(A)$Find a number $0x<14$thatsolvesthecongruence$9x9(mod14)$.$(B)$Find a number $0x<5$thatsolvesthecongruence$3x4(mod5)$.$(C)$Find a number $0x<1000$thatsolvesthecongruence$999x998(mod1000)$.$(D)$Find a number $0x<21$thatsolvesthecongruence$4x17(mod21)$.

 

\left\{ \begin{array}{l} $(A)$\\ $(B)$\\ $(C)$\\ $(D)$ \end{array} \right\}= \left\{ \begin{array}{lcr} x&=&1\\ x&=&3\\ x&=&2\\ x&=&20 \end{array} \right\}, \small{\text{ because } \left\{ \begin{array}{lcr} 9\cdot 1 &\equiv& 9 \pmod{14}\\ 3\cdot 3 &\equiv& 4 \pmod{5}\\ 999\cdot 2 &\equiv& 998 \pmod{1000}\\ 4\cdot 20 &\equiv& 17 \pmod{21}\\ \end{array} \right\}

 

heureka Jul 31, 2015

2 Online Users

avatar