3.1
var
x, a, b, c: real;
begin
readln(x, a, b, c);
writeln('y = ', (sqr(a - 4) * (1 / (x * x * x)) - 3 * sqr(b) * x) / (a * x + b) + 3 * (1 / sqr(a)) - ln(x));
end.
3.2
var
a, h, b, c: real;
begin
readln(a, h);
c := 2 * sqrt(sqr(a) - sqr(h));
b := a;
writeln('P = ', a + b + c);
writeln('S = ', 0.5 * sqr(a));
end.
6
var
n, t: byte;
g: integer;
begin
readln(n);
for i: byte := 1 to n do
begin
readln(t);
g := g + t;
end;
writeln(g / n:0:1, ' г.');
end.