<%= form_with model: @article do |f| %>

  <div class="form-group push-down">
    <%= f.label(:article_title, :article_title.t + ":") %>
    <%= f.text_field(:title, class: "form-control") %>
    <div class="help-block">
      <%= :form_article_title_help.t %>
      <%= :field_textile_link.t %>
    </div>
  </div>

  <div class="form-group push-down">
    <%= f.label(:article_body, :article_body.t + ":") %>
    <%= f.text_area(:body, rows: 10, class: "form-control") %>
    <p class="help-block"><%= :field_textile_link.t %></p>
  </div>

  <%= f.submit(:SUBMIT.t, class: "btn center-block push-down") %>

<% end %>

<%= form_with model: @article do |f| %>

  <div class="form-group push-down">
    <%= f.label(:article_title, "#{:article_title.t}:") %>
    <%= f.text_field(:title, class: "form-control") %>
    <div class="help-block">
      <%= :form_article_title_help.t %>
      <%= :field_textile_link.t %>
    </div>
  </div>

  <div class="form-group push-down">
    <%= f.label(:article_body, "#{:article_body.t}:") %>
    <%= f.text_area(:body, rows: 10, class: "form-control") %>
    <p class="help-block"><%= :field_textile_link.t %></p>
  </div>

  <%= f.submit(:SUBMIT.t, class: "btn center-block push-down") %>

<% end %>

Replace string concatenacion with interpolation
Replace string concatenacion with interpolation

One less assignment/replacement
