How do you demonstrate this
#Demonstration
rose geyser
cosmic patrolBOT
How do you demonstrate this
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+close - Feel free to nominate the person for helper of the week in #helper-nominations
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rose geyser
The only hint we were given is that 7*u ≡ 1 (26) is valid with u = 15
and I have to do it for tomorow but idk if someone will be able to read it
worthy sparrow
The only hint we were given is that 7*u ≡ 1 (26) is valid with u = 15
right, so that shows $7^{-1}=15\mod 26$
hence $7x\equiv j\mod 26\to 15(7x)\equiv15j\mod 26\to x\equiv15j\mod 26$
rose geyser
right, so that shows $7^{-1}=15\mod 26$
thanks btw
muted mossBOT
@rose geyser has given 1 rep to @worthy sparrow
rose geyser
So I assume to prove it from the right side to the left I use the same procedure
wait but how can we affirm 7^-1 = 15
prisma pierBOT
ℝafain
mild tulip
Hence given $7x\equiv j\pmod{26}$,
$$x\equiv 105x=15\cdot 7x=15j\pmod{26}$$
prisma pierBOT
ℝafain
mild tulip
The converse can be similarly proven.
mild tulip
wait but how can we affirm 7^-1 = 15
What does the notation 7^(-1) mean?
mild tulip
The only hint we were given is that 7*u ≡ 1 (26) is valid with u = 15
Is it any different from the statement given in the hint?
rose geyser
What does the notation 7^(-1) mean?
Exponent
worthy sparrow
What does the notation 7^(-1) mean?
the multiplicative inverse of 7
worthy sparrow
the same thing it always means
worthy sparrow
that's why you dont take over help channels
mild tulip
~~that's why you dont take over help channels~~
I am not the one misunderstanding multiplication in (Z_26, +, *), it's op
worthy sparrow
they never said they misunderstood it
but again, you dont need to nor should take over help channels
mild tulip
They are still misunderstanding what 7^(-1) means
worthy sparrow
so then I can respond to them
cause im the one helping here
Like did your school(s) have random teachers barge into other classrooms and just take over?
mild tulip
cause im the one helping here
Are the help channels designed as such? I always understood the no-DM rule to be based on how multiple helpers can help
worthy sparrow
I mean it's common sense
2 people trying to help one person is rarely fruitful
it's also just... courtesy
mild tulip
I mean there was a 45+ minutes gap, in your analogy this is a different lesson already
worthy sparrow
sure whatever
anyway you can leave cause im here, and the one who is/was helping them
worthy sparrow
wait but how can we affirm 7^-1 = 15
like I said, and your hint suggested, $7^{-1}$ is the unique number $u$ such that $7u=1\mod 26$, to which you were told $u=15$ does that
prisma pierBOT
Omegabet_
worthy sparrow
hence why 7^-1 is 15
rose geyser
ahh i see
worthy sparrow
alternatively, you can just check that $7(15)\equiv 1\mod 26$
prisma pierBOT
Omegabet_
rose geyser
Oh yeah that works indeed
potent anvilBOT
Unable to parse the channel name
rose geyser
+close