.
and 
.
lie on a circle with centre 
.
are collinear.
such that, for all positive integers 
and 
,
be a positive integer. We say that 
such that:
for which![\[
a \mid s^b - l.
\]](http://latex.artofproblemsolving.com/5/d/9/5d9db7678c54d1c6a909b4aca39a329cadd71e2c.png)
2. For every proper divisor 
of 
and 
)![\[
a' \mid s^b - l.
\]](http://latex.artofproblemsolving.com/4/b/2/4b26b9bd3da8958287703c3f575bf5d5da7fd477.png)
Determine all bao-good positive integers 
such that![\[(a^2 + b^2 + c^2)^2 = 3(a^3b + b^3c + c^3a) + 1. \]](http://latex.artofproblemsolving.com/9/e/4/9e400fd807a9535ede983b75dcc307d8b75a35b6.png)
Y by
The trapezoid 
with bases 
and 
is given. On the side of the 
is arbitrary noted the point 
is the point of intersection of the lines 
and 
. On the side 
, mark the point 
so that that 
. Denote by 
the point of intersection of the lines 
, by 
the point of intersection of the lines 
. Prove that the lines 
and intersect at one point.
(Vyacheslav Yasinsky)
with bases 
and 
is given. On the side of the 
is arbitrary noted the point 
is the point of intersection of the lines 
and 
. On the side 
, mark the point 
so that that 
. Denote by 
the point of intersection of the lines 
, by 
the point of intersection of the lines 
. Prove that the lines 
and intersect at one point.(Vyacheslav Yasinsky)
This post has been edited 2 times. Last edited by parmenides51, Jul 14, 2020, 10:03 PM
of 
to another plane 
so that the image of 
.It suffice to show that 
.
.
