# Align environment not working

I answered someone's question, and wanted to use the align environment. For some reason, it's not letting me. The link to the question is below. You can see in my answer that the TeX code is what shows up rather than the actual formatted math. Can anyone help me fix this?

Determine whether each of $V_1$, $V_2$, $V_3$ is a subspace of $\mathbb{R}^4$

• There cannot be blank lines in a math block, just remove them. Though I'm not sure what that "________" is for (which is why I don't dare edit your post myself). – Najib Idrissi Mar 14 '15 at 17:20
• @NajibIdrissi Haha. I wanted to be a short underline, like when you set up equation addition. Sometimes you underline the two things you are adding and put the answer below. – layman Mar 14 '15 at 17:21
• Are you talking about something like this: $\underbrace{1+1}_{= 2}$? I achieved that with \underbrace{1+1}_{= 2}. – Najib Idrissi Mar 14 '15 at 17:24
• @NajibIdrissi No, but your suggestion about the line breaks was right. See my updated answer. Now it looks more like what I wanted it to look like. – layman Mar 14 '15 at 17:25
• Ah I see, okay. glad to see it's been solved. – Najib Idrissi Mar 14 '15 at 17:25
• @NajibIdrissi By you. Thanks! – layman Mar 14 '15 at 17:26
• I made an edit. Is that what you wanted? – dustin Mar 14 '15 at 17:42
• @dustin I don't really see that your edit made much of a difference, but thank you in any case. – layman Mar 14 '15 at 17:47
• It spaced what you were adding away from the plus sign and gave proper spacing around the equal sign on the bottom row. – dustin Mar 14 '15 at 17:48
• @dustin Ok, thanks. It's always nice to have neater formatting. – layman Mar 14 '15 at 17:48