Final answer:
The variable is written first in an inequality solution because it's a mathematical convention, similar to grammar in language, ensuring clarity and consistency in mathematical communication.
Step-by-step explanation:
In math, the convention to write the variable first in an inequality solution is best explained by option B: It's a mathematical convention. Similar to the underlying rules of grammar in forming a coherent sentence, mathematical conventions are established for clarity, consistency, and ease of communication. By writing the variable first, it makes it easier for all who are reading the mathematics to immediately understand which variable is being solved for or bounded by the inequality. These conventions, like using H or H₁ for alternative hypotheses, ensure that mathematical expressions and conclusions are understood universally. Even though symbols like x, n, t, or M are arbitrary and can be chosen flexibly as long as their use is consistent, the structure of equations and the order of terms are standardized to avoid confusion.
This is akin to arranging words correctly to form a meaningful sentence. If the order of words is rearranged, the sentence meaning can become unclear or nonsensical; the same happens in mathematics if the conventional order of terms in an equation or inequality is not followed. Therefore, putting the variable first is not just about aesthetics (option A) or an absolute ease of reading (option C), and while it theoretically doesn't matter (option D), following the convention enhances mutual understanding in mathematical communication.