Help
I have a test tomorrow and I cant understand mathematical proofs.
How do I prove that 3|x ^ 5|x => 15|x ??
please explain
Help
Hunter White
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Dominic Nguyen
Best case scenario: you're fucked.
Angel Hill
git gud
Jace Barnes
Check your notation, what you've written makes no sense.
Leo Ward
It does, if 3 divides x and 5 divides x, prove that 15 divides x as well
Robert Sanchez
[math]3|x\ \text{and}\ 5|x[/math]
[math]\implies \exists\ (k, k')\in \mathbb{N}^2, x=3k=5k'[/math]
[math]\implies k=\frac{5}{3}k'\in \mathbb{N}[/math]
[math]\implies \exists\ k''\in \mathbb{N}, k'=3k'' [/math]
[math]\implies x=5k'=5\times3k''=15k'' [/math]
[math]\implies 15|x[/math]
Aaron Lee
x divisible by 3 => x = 3a for some integer a.
x divisible by 5 => x = 5b for some integer b.
So x = 3a = 5b but since a and b are integers this also means a|5 and b|3.
a = 5c for some integer c =>
x = 3a = 3*5c = 15c
=> x|15.
Kayden Williams
dumbass we are all here thinking you mean absolute value not division. use / for division.
Lincoln Barnes
so basically OP means (3/x^5)/x=15/x
Jayden Wilson
Thomas Moore
i don't see any reason to help someone who can't even type his question in some easily comprehendable manner (hint: use latex)
Charles Lee
Straight line is also used for divisibility (not division). By ^ OP clearly also means the AND operator.
This is basic algebra.
Angel Myers
> (3/x^5)/x=15/x
Gavin Lopez
use latex
fucking caveman
Carson Collins
It's because 3 and 5 are relatively prime.
Factor x into primes. You will have 3 and 5 there. Therefore you'll have 3*5 as well.
Aiden Moore
No.
For "a divides b" you either write a|b or a\b. Never a/b cause that's retarded; it looks like a fraction.
Matthew Hernandez
a fraction is division
Ryan Butler
Mike "the electrical engineer who will fix that queer" Pence
Owen Sanchez
to write it out more clearly
x=5m and x=3n
from this you have that 3|5m
because 3 and 5 are relatively prime, you get that 3|m (m=3m') ****
therefore x=5*3*m' which shows that 15|x
Caleb Price
a divides b iff b/a is an integer, not a/b
that's why a/b is a retarded notation for "a divides b" and that's why nobody uses it.
Nicholas Peterson
no that's okay. it's the use of '^' to mean 'and' that is whacky and forces the interpretation of '|' as absolute value delimiter. for OP's benefit: '^' means exponentiation. use /\ or & if you feel too cool to just type 'and'.