To construct a two-variable equation based on the given situation involving the number of board books purchased (x) and the number of soft cover books purchased (y), we would need more details about the relationship between the two variables, such as costs, total amount spent, or other conditions.
For example, if you had information about total spending, such as: "If each board book costs $5 and each soft cover book costs $10, and a total of $50 was spent on books," the equation could be:
\[ 5x + 10y = 50 \]
If you provide more context or specific details about the situation, I can help refine or create the equation accordingly!