(x,y)→(x-4,y) means that the x coordinate of each point is shifted to the left by 4 units. Pretend the point is (0,0). According to this then, it would be (-4, 0) which would move the point to the left by 4.
The vertex for the actual or parent graph is (2,1). The translated vertex would be (2-4, 1) or (-2,1)
The graph that has that vertex is the second page, bottom one with a point at the bottom at (-2,1)
Hope this helps.
