Got an assignment stuck don't know why it is not working?
How do I compare strings in Java?
File changed listener in Java Double booked - User bookmarking question recorded twice SSH to open GUI on target machine? Is it possible to add an email just below the authors in this code?  \documentclass[11pt,oneside,a4paper]{article} \usepackage{hyperref}   \title{Hello} \author{User1 \and User2}    \begin{document} \maketitle  \section{Introduction} A1 \section{Literature Review} A2  \section{Conclusion} A2  \end{document} I just upgraded to Ubuntu 18.04 but the UI did not change at all. For example I don't have the full screen app launcher; it's the same as it was back in 16 and 17. No notification center etc.   Do I need to somehow opt in? How should I successfully hibernate Ubuntu 16.04?  I've tried almost every solution on the web but non of them was actually helpful. I found my problem almost completely similar to $n\ge 8\,\Rightarrow\, n = 3j + 5k\ $ for $\,j,k,n\in \Bbb N$ I'm new to Math Induction, I don't know how it goes from $𝑘 + 1 = 3𝑥 + 5𝑦 + 1$ into $5𝑦 = 5𝑦 − 5 + 5.$  I'm trying to prove that:   Any whole number of at least 8 cents can be obtained using coins of 3 and 5 cents  Assume: There is a number $𝑘$ for which there are $𝑥$ and $𝑦$ such that $𝑘 = 3𝑥 + 5𝑦$  Here's my working:  $𝑘 = 3𝑥 + 5𝑦$  Therefore $𝑘 + 1 = 3𝑥 + 5𝑦 + 1$  $5𝑦 = 5𝑦 − 5 + 5$  $5𝑦 = 5 𝑦 − 1 + 5$  $𝑘 + 1 = 3𝑥 + 5𝑦 + 1$  $𝑘 + 1 = 3𝑥 + 5(𝑦 − 1) + 5 + 1$  $𝑘 + 1 = 3𝑥 + 5(𝑦 − 1) + 6$  $𝑘 + 1 = 3(𝑥 + 2) + 5(𝑦 − 1)$  $𝒌 + 𝟏 = 𝟑𝒙' + 𝟓𝒚'$ I need to find a reg ex that only allows alphanumeric. So far, everyone I try only works if the string is alphanumeric, meaning contains both a letter and a number. I just want one what would allow either and not require both. How to play MP3 files using Rhythmbox? Show that the set of all polynomials whose constant term is a multiple of 3 is an ideal of the ring $Z[x]$.   Attempt: Suppose then we need to show   if $p(x), q(x) \in I$ then $p(x) + q(x) \in I$  and if $r(x) \in Z[x]$ , then $p(x)r(x) \in I$ and $r(x)p(x) \in I$.  And $0 \in Z$, then $0 \in I$.  Then let   $I =$ {$a_nx^n + a_{n-1}x^{n-1} + ...+a_1x + a_0$ | $a_i \in Z$, $a_0\in 3Z$}  $p(x)  = a_nx^n + a_{n-1}x^{n-1} + ...+a_1x + 3a$  and $q(x) = b_mx^n + b_{m-1}x^{n-1} + ...+b_1x + 3b$  Here we do not assume that $p(x) $ and $q(x)$ have the same degree.  Then $p(x) + q(x)  = [a_nx^n + a_{n-1}x^{n-1} + ...+a_1x + 3a]  +  [b_mx^n + b_{m-1}x^{n-1} + ...+b_1x + 3b] = 3(a + b) + (a_1 + b_1)x + ....+ (a_n + b_m)x^n$.  so $p(x) + q(x) \in I$  And $0 \in Z$ is also in $I$, since for $p(x) = 0x^n + ....+ 3(0) = 0$.  And let $r(x)= c_nx^n + ...+3c  \in Z[x] $.  Then $r(x)p(x) = 3(3ac) + (3b_1 + 3a_1) + ....+ a_nb_mx^{2n}$  So $r(x)p(x) \in I$.  Can someone please help? I am not really sure how to prove this. I am getting confused with the underscrips Any help or better approach would really help. Thanks in advance! How to calculate such sums of Legendre symbols? Can some metadata about deleted posts be included in Data.SE? I like to use  to view usage stats for some of the sites, however deleted posts are not included on Data.SE and I think this skews the numbers quite a bit, particularly on sites with a lot of deletions. Would it be possible to include some limited data about deleted posts in Data.SE to make statistical queries more accurate? You could clear the non-public data fields of deleted posts, such as Posts.Title, Posts.Body, and Posts.OwnerUserId to address privacy concerns explained . You could even leave the PostId set to 0 since I know SE doesn't want to provide users with a way of searching deleted questions. The data I would mostly be interested in is CreationDate, LastActivityDate, PostHistory (date closed, date reopened, date deleted, etc), and the fact there was a deleted question in the first place. Up/Down votes, Score, Tags, and View/Answer/Favorite count would also be preferred. This would make the statistical queries accurate, while still removing the information not meant to be visible to the public. Allow users to put their e-mail in posts? Should I edit out the (thankfully obsfucated) e-mail address from this ?  Is this something we should allow on the site going forward?  I don't care about the "thank you" or "hello", but this might lead to an answer being sent by e-mail, which would mean it wouldn't be peer reviewed (for what that's worth), and the answer would be lost to the community. How do I get a platform-dependent new line character? How do I get a platform-dependent newline in Java? I can’t use "\n" everywhere. I'd like to find a place to store stuff while I'm out adventuring, without spending 5000 on a house (at least, until I can afford that...). Where can I safely store items without worrying about them disappearing?   There are two possible places that come to mind,  (to which I have the key and was told I could stay), and the small bedroom given to me at the  (which I was told was mine, despite seeing J'zaro sitting in it later). Can I store items safely in either of these places? How to set selected Dialog values to TextViews in Fragment How can I tell what RAM will fit my computer? If I want to add more RAM to my computer, how can I buy something compatible? What kinds are there? How do I determine which kind my computer will accept and how much I can add? How to evaluate  $$\det\begin{bmatrix}1+x_1y_1&amp;\cdots &amp; 1+x_1y_n\\ \vdots &amp; \ddots &amp; \vdots \\ 1+x_ny_1 &amp; \cdots &amp; 1+x_ny_n\end{bmatrix}$$?  I tried factorisation but I have no idea. I could not factor anything out... I need a hint to kick off.   Edit: A conjecture due to multilinearity: if we let $v_j=(x_1y_j,\cdots,x_ny_j)^T$, then my guess would be $$\det\begin{bmatrix}1+x_1y_1&amp;\cdots &amp; 1+x_1y_n\\ \vdots &amp; \ddots &amp; \vdots \\ 1+x_ny_1 &amp; \cdots &amp; 1+x_ny_n\end{bmatrix}=\det(1,v_2,\cdots,v_n)+\det(v_1,1,\cdots,v_n)+\cdots+\det(v_1,v_2,\cdots,1)=\color{red}{0}$$ where $1$ denote $(1,\cdots,1)^T\in \Bbb K^n$,$\Bbb K$ the underlying number field. When you tap a row in a UITableView, the row is highlighted and selected. Is it possible to disable this so tapping a row does nothing? Why can't you use a single resistor for a number of LEDs in parallel instead of one each?