Final answer:
This question involves creating a mathematical expression to represent Bill and Raj buying a baseball and x pairs of sweat socks, typical of a high school Mathematics algebra problem.
Step-by-step explanation:
The question given pertains to Bill and Raj who are on a baseball team and each bought a baseball and x pairs of sweat socks. The subject matter involves creating a mathematical expression or equation to represent the scenario, likely for a purpose such as cost calculation or comparisons. Questions such as these typically fall under the subject of Mathematics, more specifically within the realm of algebra where variables are used to represent unknown or variable quantities.
Questions like this are common in high school level mathematics, where students learn to convert word problems into algebraic expressions and develop problem-solving skills. The scenario described is used to construct real-life contexts where algebraic reasoning is applied.