Достаточно быстро?:)
1)
var x: integer;
begin
readln(x);
if (x > 5) then writeln('y(', x, ') = ', x * x + 5);
if (x <= 3) then writeln('y(', x, ') = ', x - 8);<br>end.
2)
var x: integer;
begin
readln(x);
if (x > 0) then writeln('y(', x, ') = ', x);
if (x = 0) then writeln('y(', x, ') = ', 0);
if (x < 0) then writeln('y(', x, ') = ', -1 * x * x);
end.
3)
var a, b, c: real;
begin
readln(a, b);
c := sqrt(a*a + b*b);
writeln(a + b + c);
end.
4)
var a, b, c: real;
begin
readln(a, b);
if (b <> 0) then c := a / b;
writeln(c);
end.