The expression (x - x_1)(y_2 - y_1) represents a mathematical operation involving two variables, x and y. Here, x_1 is a specific value of x, while y_1 and y_2 are specific values of y. This expression can be used in various contexts, such as calculating the change in a coordinate system or determining the slope of a line. In geometry, this expression can help describe the relationship between points in a two-dimensional space. For example, if (x_1, y_1) and (x_2, y_2) are points on a graph, then (x - x_1)(y_2 - y_1) can be useful for finding the area of a rectangle formed by these points. Understanding this expression is essential for solving problems related to geometry and {