We have the old math topic by @BuildASnowman, we could use that one.

# The Numberphile Topic -- The Official Nerdy Math Topic! [OLD]

**FearlessPhoenix**#425

The things that math teachers put on homeworks...

Like, really!

If 3m=5a, and m-a=80, what is the value of m?

I could go on and start to rant, but, I'll save you guys and won't...math is too easy for me..

**Gobli09**#426

I have a math question that is kind of hard-ish if you haven't ever heard of 3d plane figures before in graphing. Below there are three simultaneous equations. Solve for x, y and z. Then graph the equations on an xyz grid.

3x+2y-3z=2

-x+4y-3=2z

-2x-y+2z=0

**MR.GAM3R**#427

I am trying to find out the angles of a triangle based on the lengths of the sides. I found this:

Let △ABC have sides a, b, and c.

We are using the usual convention that the length of the side

opposite vertex A is called a, and so on.

Let θ=∠C. Then the Cosine Law says that

c^2 = a^2 + b^2 − 2ab cosθ`

So how do you reverse this to get θ?

**t1_hopscotch**#428

Oooh that is a very great question.

...can I suggest an idea? Looks like θ is a variable in that equation, like x or y might be.