It doesn't "stand for" anything. And wrong category.
An unknown or variable (n) multiplied by 10
It doesn't stand for bananas.
3000
metre
elementary maths
answer is maths.
maths economics comers
An unknown number.
LCM stand for Least Common Multiple
Base times Height
Small/lower case 'x' means nothing in Roman Numerals. Capital 'X' means ' 10'. NB All the letters used in Roman Numerals are ALWAYS CAPITAL letters. Lower case letters do not mean a thing.
Terrible teachers failing maths