System of non-linear equations

[Gabriel]

Then why the intervals worked for fsolve([cos(x)-x,x-y],[x=0..1,y=0..1]?
Anyway I tried single values this way:
fsolve([39.8344274/(y-0.1495645628)-24.52151/(y^2)=39.8344274/(x-0.1495645628)-24.52151/(x^2),39.8344274/(y-0.1495645628)-24.52151/(y^2)=39.8344274*ln((x-0.1495645628)/(y-0.1495645628))/(x-y)-24.52151/(x*y)],[x,y],[0.8,0.25]) and I got my solution(why did you say it was slow, it was quite fast), and for some unknown reasons its important that i put an accurate y value, for example if i put 1.66 and 0.2 i doesnt work, while it works with 0.8 and 0.25