Current Events > Where's the mathematical flaw in this explanation?

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FLOUR 11/04/23 3:33:46 PM #1:	A teacher is explaining how to find positive integers less than 15 that satisfy the equation x^2=1 (mod 15). He then shows that x^2-1=0 (mod 15), (x-1)(x+1)=0 (mod 15), and thus either x-1=0 (mod 15) or x+1=0 (mod 15). Solving for x, he shows the two solutions to the problem are x=1 and x=14. Where's the flaw in his reasoning? --- You wish to fill Lionel's coffers? Yes, ha, ha, ha, yes!!! <cite>FLOUR posted [p:977032134] in Where's th... [t:80611358]...</cite> <quote>A teacher is explaining how to find positive integers less than 15 that satisfy the equation x^2=1 (mod 15).He then shows that x^2-1=0 (mod 15), (x-1)(x+1)=0 (mod 15), and thus either x-1=0 (mod 15) or x+1=0 (mod 15). Solving for x, he shows the two solutions to the problem are x=1 and x=14. Where's the flaw in his reasoning? </quote> ... Copied to Clipboard!
Sariana21 11/04/23 3:46:12 PM #2:	What does (mod 15) mean? --- ___ Sari, Mom to DS (07/04) and DD (01/08); Pronouns: she/her/hers <cite>Sariana21 posted [p:977032359] in Where's th... [t:80611358]...</cite> <quote>What does (mod 15) mean? </quote> ... Copied to Clipboard!
DementedDurian 11/04/23 3:53:57 PM #3:	We're not doing your homework for you. --- (She/Her) I'm a succubus. Don't worry, I'm not going to hurt you. <3 Video Game IGN: Mystic. Ask me for a joke, I come up with some good ones. <cite>DementedDurian posted [p:977032490] in Where's th... [t:80611358]...</cite> <quote>We're not doing your homework for you. </quote> ... Copied to Clipboard!
LordFarquad1312 11/04/23 4:40:10 PM #4:	Sariana21 posted... What does (mod 15) mean? a=b (mod n) means that the residual of a/n is b For example, 17=3 (mod 7) since 17/7 is 14 and the reminder is 3. --- El sexo sucio y el planeta limpio. "If you are tired of fear from links... Let Kirby's Nightmare protect you." <cite>LordFarquad1312 posted [p:977033257] in Where's th... [t:80611358]...</cite> <quote>Sariana21 posted... </cite><quote>What does (mod 15) mean?</quote>a=b (mod n) means that the residual of a/n is bFor example, 17=3 (mod 7) since 17/7 is 14 and the reminder is 3. </quote> ... Copied to Clipboard!
scar_the_1 11/04/23 4:42:58 PM #5:	I feel like if you have an equation where ab = 0 (mod x), then there can be more solutions than a = 0 and b = 0. Like, 35 should be 0 mod 15, no? --- Stop being so aggressively argumentative for no reason. - UnfairRepresent <cite>scar_the_1 posted [p:977033304] in Where's th... [t:80611358]...</cite> <quote>I feel like if you have an equation where ab = 0 (mod x), then there can be more solutions than a = 0 and b = 0. Like, 35 should be 0 mod 15, no? </quote> ... Copied to Clipboard!
lderivedx 11/05/23 7:12:12 PM #6:	Z/15Z is not a field and has zero divisors --- i cant get off unless we're violating at least four OSHA regulations <cite>lderivedx posted [p:977053783] in Where's th... [t:80611358]...</cite> <quote>Z/15Z is not a field and has zero divisors </quote> ... Copied to Clipboard!
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