I see this question https://mathematica.stackexchange.com/questions/304317/how-to-draw-a-number-of-circles-inscribed-in-a-square-so-that-the-sum-of-the-rad

I have a square with length of side is $a$. How to draw a number of circles inscribed in a square so that the sum of the radii of the circle is greatest? In the below picture is twenty circles inscribed in a square. We can consider number of circles are 5, 6, ... We consider number of the circles is fixed.

How can I tell Maple to do that.

At here https://mathematica.stackexchange.com/questions/297104/how-can-i-convert-a-list-containing-three-points-and-its-equation-passing-three is discussing about "How can I convert a list containing three points and its equation passing three points to text file?" With mylist

mylist := [[[-12, 2, -1], [-11, 1, -5], [-10, -2, 3], 10*x + 6*y + z + 109 = 0], [[-12, 2, -1], [-11, 1, -5], [-10, 6, 3], 2*x - 2*y + z + 29 = 0], [[-12, 2, -1], [-11, 1, -5], [-9, 5, -7], 3*x - y + z + 39 = 0]]

How can I get the LaTeX file like this?

\documentclass[12pt,a4paper]{article}
\usepackage[letterpaper,margin=1.2in]{geometry}
\usepackage{enumitem}
\begin{document}
\begin{enumerate}[label=\arabic*)]
\item $A(-12; 2; -1)$,\quad $B(-11; 1; -5)$,\quad $C(-10; -2; 3)$,\quad $(P) : 10 x+6 y+z+109=0$
\item $A(-12; 2; -1)$,\quad $B(-11; 1; -5)$,\quad $C(-10; 6; 3)$,\quad $(P) : 2 x-2 y+z+29=0$
\item $A(-12; 2; -1)$,\quad $B(-11; 1; -5)$,\quad $C(-9; 5; -7)$,\quad $(P) : 3 x-y+z+39=0$
\end{enumerate}
\end{document}

Let S1: x^2 + (y - 2)^2 + (z + 1)^2 = 29 be a sphere and two points A(0, 0, 4), B(6, -2, 6); the line d passing through point C(4, -8, 4) and have direction v=(1, -1, 2). Find the point M such that M lies on the sphere S1, the angle AMB equals to 90 degree and distance from M to the line d is minimum. 

This is my code
 

restart;
with(Student:-MultivariateCalculus);
A := [0, 0, 0];
B := [a, 0, 0];
C := [a, a, 0];
DD := [0, a, 0];
S := [0, 0, h];
d1 := Line(A, C);
d2 := Line(S, DD);
(Distance(d1, d2) assuming (a::positive and h::positive));

I got 

abs(a)^2*abs(h)/sqrt(2*abs(a*h)^2 + abs(a)^4)

How can I remove abs?

How can I find a relation of a, b, c, d, t (a d <> 0) so that the function f(x) = (a x^2 + b x + c)/(d x +t) is a increasing function on the interval (m, n)? I know that, we have the conditions 
f'(x) >=0 forall x in (m, n) and -t/d not in (m, n).