Melody

Civonamzuk, thanks for these interesting questions.

If you write serial questions like this could you please link them with the web address of the others.

So a person can see the whole thing?

This was the original post.

I have included this question in the Puzzle Thread

This question is continued here

Yes I think this is quite hard M.G.  

It looks like a good puzzle.  I will add it to our puzzles thread   

You have posted this here

Thanks EinsteinJr,

I have watched those videos and they are interesting but they start out with premises that they do not even attempt to prove.  Not on those clips anyway.

Why do you accept that 1-1+1-1+....... = 0.5    ?      (Edited)

I think that you have posted this twice MathsGod1.

You know I get annoyed when people do that.    

Thanks Chris,

This can be easily done by any good yr 9 student.

$$\\\boxed{(a+b)^2=a^2+2ab+b^2}\\\\
so\\\\
(3x+(2y+1))^2\\
=(3x)^2+2*3x*(2y+1)+(2y+1)^2\\
=etc\\\\
$The only term with xy is going to be $ \\
2*3x*2y=12xy\\
$so the coefficient of xy is 12$$$

EinsteinJr and Daedalus

WHAT ARE YOU TWO DOING  ?????

The sum of every positive integer is infinity.