You can view lessons in "reference mode" -- to get there, just click on the old task and then on the name of the topic.
You can also get there from the Table of Contents -- to get there, go to your dashboard (where your learning tasks are), click on the name of your course in the top-left, and you'll be brought to a screen that says "Course Sequence" with a list of courses on the left and units on the right. If you expand the units, you'll see topics, and you can click on a topic to view its lesson in reference mode.
Note that XP & knowledge credit is only awarded for completing learning tasks on your dashboard, not for anything you do within a lesson in reference mode.
Not sure, but looking at the interface myself just now, it seems like it's always possible to see the latex of a math field by either
1) right-click > show math as > tex commands (which you can copy/paste), or
2) hover over the field and see the tex commands show up as hover text (but can't copy/paste)
You can also get there from the Table of Contents -- to get there, go to your dashboard (where your learning tasks are), click on the name of your course in the top-left, and you'll be brought to a screen that says "Course Sequence" with a list of courses on the left and units on the right. If you expand the units, you'll see topics, and you can click on a topic to view its lesson in reference mode.
Note that XP & knowledge credit is only awarded for completing learning tasks on your dashboard, not for anything you do within a lesson in reference mode.