Echo HTML within PHP where to place quotes

Echo HTML within PHP where to place quotes

I'm doing something wrong with the first line, its the quotes:
<td><? echo"<a href='edit.php?id=" . "$row['adminuser_id']" .
"'>Edit</a>";?></td>
should work as this works
echo '<td><a href="edit.php?id=' . $row['adminuser_id'] . '">Edit</a></td>';