Вот программа:
uses Crt;
var x, a, y, d, z: real;
n: integer;
begin
ClrScr;
Write (' n = ');
ReadLn(n);
if (n<1) or (n>7) then WriteLn( 'None...') else
begin
x:=0.5;
a:=4.3;
y:=2.6;
d:=0.3;
if (n=1) then z:=a-x+y/d else
if (n>1) and (n<5) then z:=1.5*x+9*x*x-1.25 else<br>if (n>4) and (n<8) then z:=d-a*sin(x);<br> WriteLn(' z = ', z:6:3);
end;
ReadLn;
end.