Первая задача
var a,b,x,y,z:
real;
begin
write ('х=');
read (x);
write('y=');
read (y);
write ('z=');
read (z);
a:= (x+y-z)/(x*x+2);
write ('a=');
write (a:1:2); end.
Вторая
var a,b,x,y,z:real;
begin
write ('х=');
read (x);
write('y=');
read (y);
write ('z=');
read (z);
a:= 5*((2*x-z)/(3+y*y));
write ('a=');
write (a:1:2);
end.