What is eck?
Numbers, negatives, plus minus times divide, the percents and fractions of munmath, you think you’re pretty quick with that stuff, well, congratulations idiot, that’s just the first room. Step into the nextroom and you’ve got letters running around in there, letters that might mean a number and might not, so have fun dealing with that. Sometimes you solve for ecks, ecks is a mystery criminal you have to catch, sometimes else it’s not a crimeshow it’s a lovestory, ecks is in a relationship with why.

Q1: Is eck an angle?
Q2: What is 'sometimes else it’s not a crimeshow it’s a lovestory'?

Question

What is eck?
Numbers, negatives, plus minus times divide, the percents and fractions of munmath, you think you’re pretty quick with that stuff, well, congratulations idiot, that’s just the first room. Step into the nextroom and you’ve got letters running around in there, letters that might mean a number and might not, so have fun dealing with that. Sometimes you solve for ecks, ecks is a mystery criminal you have to catch, sometimes else it’s not a crimeshow it’s a lovestory, ecks is in a relationship with why.

Q1: Is eck an angle?
Q2: What is 'sometimes else it’s not a crimeshow it’s a lovestory'?

Answer

ecks=X
why=Y

sometimes math requires you to "solve for X", like a detective solves a murder.
Sometimes you are asked to find the relationship between X and Y, just as people watching a love story try to find  out who will be in a relationship with whom.

Answer

ecks is X.
'sometimes else' I assume is 'at other times'.
Later, they use 'why' to mean 'Y'. X and Y from mathematics.
I pity you... Reading this would be bad enough...

Answer

I've never seen "ecks" before, thank you for asking the question, most people would use X or x, but hey.  You seem to have a number of other words that I suspect don't exist
munmath, nextdoor, crimeshow, lovestory and I've just spotted "why" spelt Y or y.