Irrational
.
4:5 is a ratio that can also be written as 4/5 or, as a decimal, 0.8
How about (44 - 4)/4?
I don't think a graphical solution is "cheating" - it seems perfectly valid to me. However, if you want a non-graphical method then here is a possibility:
(That last d should be a δ, of course!)
The gaps in the following graph show that x.floor(x) = M has a solution for some values of M, but not others:
In general: xm*xn = xm+n
See if this helps:
One of these?
Perhaps 2: an inside and an outside!
If the first is meant to be 11*5 = 55 and the second is 0.0011*5 = 0.55 then the second is wrong! It should be 0.0011*5 = 0.0055