The line x = 4 is a vertical line on the coordinate grid which passes through the x-axis at the point where x = 4.
So the x coordinate of Q will be the same distance after x = 4 as P is before it. That is where x = 4+2 = 6. The y coordinate will be the same as that of P.
(Imagine that the line x = 4 is a mirror, then Q is the image of P).
2/3 is a fraction and shows the parts of a whole. This means that 2/3 of last week is fewer than last week. Last week is the whole for example 15 hours. This week will be 2/3 or 2/3*15 = 10 hours. This week will be less than last week.
