# Can I put formula numbers in a question or an answer?

Suppose I'm writing a question like

blah blah blah $$a=0$$ blah blah blah

I want to put (1) at the very right of the line that has $$a=0$$. Can I do that?

blah blah blah

$$a=0 \tag{1}$$

blah blah blah

To get the above, use \tag{*insert number/label here*} at the end of the formula, like the following:

blah blah blah

$$a= 0\tag{1}$$

blah blah blah

• Thanks! Can I ask you one more question? How do you put those horizontal lines between paragraphs? – zxcv Oct 19 '18 at 23:34
• You can do that by writing a dashed line --------- (doesn't have to be long like the entire width of the page, just a handful of -'s). Also, when you are composing a post, you'll see a menu along the top, the menu with images. One shows grey lines, above and below, separated by a dashed line. Clicking on that will give you a horizontal line, like you see in my post. – Namaste Oct 19 '18 at 23:39
• To get the equation number in math format use tag{$1$} ... for example if you want the tag to be $1'$ you will need the dollar signs there. – GEdgar Oct 20 '18 at 14:35