Yh infact charcot explained it a lot better than I did. Let me try and explain it a bit better with simpler numbers. So, let's say that 6 x 9^2 = 486 right. Now let's double the 9 and halve the 486, so we have 6n x 18^2 = 243. We need to find 'n' now to make the equation work, so 18^2 = 324, 243/324 = 0.75. So this means that 6n = 0.75, thus n = 0.75/6 = 1/8. So that just proves why you need to divide A by 8 when B doubles and the rate halves. Do you see a bit better now?