What expression is equivalent to (64y^100)^1/2

The ratio pv to nrt is plotted against pressure for ch4 at 0°c and 200°c. why does the curve for 0°c drop below the horizontal line for an ideal gas whereas the curve for 200°c does not?

In the diagram, the ratio of ab to ae is (1/2) . what is the ratio of the length of to the length of ?

2y= 3 2 x−2 y = − 1 3 x + 1 y=− 3 1 x+1