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0 votes
2 answers
427 views

What I'm missing in $p=3^{q}\cdot 2^{r}$?

Given positive integer $p,q,r$ with $p=3^{q}\cdot 2^{r}$ and $100<p<1000$. The difference between maximum and minimum values of $(q+r)$ is? My tries It's clear that $p=6k$ for some positive ...
mathlover's user avatar
  • 1,943
0 votes
2 answers
242 views

How can $(2^{100}-2^{98})(2^{99}-2^{97})$ be written in terms of its prime factors?

How can $(2^{100}-2^{98})(2^{99}-2^{97})$ be written in terms of its prime factors? I tried to expand it: $2^{199}-4^{197}+2^{195}$ What do I do next? The answer choices are: A. $2^{100}\cdot3 \...
BlueMagic1923's user avatar
10 votes
5 answers
796 views

Find all the prime factors of $1000027$

Find all the prime factors of $1000027$. I got all the factors by testing every number from $1$ to $103$, but when I try to do it using algebra, I get stuck. My work: $$ 1000027=(100+3)(100^2-3\...
suomynonA's user avatar
  • 6,915
-1 votes
1 answer
32 views

Highest common factor of integers which are the same. [closed]

If $a=-b \in \mathbb{Z}, $ Then $hcf(a, b)=|a|=|b|$, right?
Gurjinder's user avatar
  • 1,319
1 vote
1 answer
29 views

Prove that $a(x)$ divides $(v(x) - t(x))$

"Let $a(x), b(x) \in \mathbb{R}[x]$, not both the zero polynomial and suppose that gcd[$a(x), b(x)$] = 1. Let $u(x), v(x) \in \mathbb{R}[x]$ be such that $a(x)u(x) + b(x)v(x) = 1$ Let also $s(x)t(x) ...
maths123's user avatar
  • 541
1 vote
1 answer
76 views

Proving the primality of these large numbers?

In 2007, Vautier claimed that the largest known consecutive pair of prime numbers (at the time) was $2003663613\cdot2^{195000}-1$ and $2003663613\cdot2^{195000}+1$. I was wondering how Vautier found ...
Simply Beautiful Art's user avatar
2 votes
2 answers
251 views

How does one prove that $(2\uparrow\uparrow16)+1$ is composite?

Just to be clear, close observation will show that this is not the Fermat numbers. I was reading some things (link) when I came across the footnote on page 21, which states the following: $$F_1=2+1\...
Simply Beautiful Art's user avatar
3 votes
1 answer
55 views

A smart way to do this question.

Let $S=\{0,1,2,\dotsc,25\}$ And $T=\{n\in S : n^2+3n+2\text{ is divisible by }6\}$ Then the number of elements in $T$ is? One way I know is to factorise it as $(n+1)(n+2)$. And then put each $n$ ...
Sudhanshu's user avatar
  • 1,567
1 vote
2 answers
124 views

The Diophantine Equation $m(n-2016)=n^{2016}$

How many natural numbers, $n$, are there such that $$\frac{n^{2016}}{n-2016}$$ is a natural number? HINT.-There are lots of solutions HINT.-$\frac{n}{n-2016}=m \iff \frac{2016}{n-2016}=m-1$ and if, ...
Piquito's user avatar
  • 30.3k
6 votes
2 answers
9k views

Total number of divisors of factorial of a number

I came across a problem of how to calculate total number of divisors of factorial of a number. I know that total number of divisor of a number $n= p_1^a p_2^b p_3^c $ is $(a+1)*(b+1)*(c+1)$ where $a,...
DCoder's user avatar
  • 298
4 votes
3 answers
113 views

Find the greatest common divisor of $2003^4 + 1$ and $2003^3 + 1$

Find the greatest common divisor of $2003^4 + 1$ and $2003^3 + 1$ without the use of a calculator. It is clear that $2003^4+1$ has a $082$ at the end of its number so $2003^4+1$ only has one factor of ...
Michael Mudarri's user avatar
0 votes
0 answers
382 views

Positive integers of sum and products

Find all pairs of positive integers $m$ and $n$ where $m<n$ such that the sum of $m$ and $n$ added to the product of $m$ and $n$ is equal to $2014$ I just thought about this question and wanted to ...
col's user avatar
  • 167
2 votes
1 answer
47 views

In $1 < k < n-10^6$, what is $k$? (details in question)

This is a homework question of mine, I am not searching for the solution but rather what it means. It seems pretty straight forward but I am a little confused as to what the $k$ in $1 < k < n-10^...
user2710184's user avatar

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