Hi mike, I don’t know how to answer questions like these; would you tell me the right way to do so?
In the xy-coordinate plane, point P is the reflection of the point with coordinates (3,1) across the line y=x. Point T is the reflection of point P across the y axis. What are the coordinates of T?
You probably won’t need this for the SAT, but the reflection of a point across the y = x line is found by transposing the points. So the reflection of (3, 1) across y = x is (1, 3). Reflect that across the y-axis by negating the x-value to get (–1, 3).