What is the sum of X+XX+XXX+XXXX?
08.06.2025 03:49

However, X +X^2 +X^3 + X^4 is a valid algebraic answer,
Given the use of upper case, I personally would initially assume Roman numerals*, so the answer would be C (100 in present-day decimal notation)
as would be assuming that these are representations of conventional numbers, in which case the answer for number bases of five or more would be
What did someone say to you that instantly made you realize their life was in danger?
1234X
What is the sum of X+XX+XXX+XXXX?
It’s a matter of interpretation.
and for binary would be
11010X
*Note that the abbreviation XL (for XXXX) appeared quite late in the Roman period, and never found universal favour