2.1
#include<stdio.h>
int main()
{
float c,f;
scanf("%f",&f);
c=(f-32)/9*5;
printf("%.2f\n", c);
return 0;
}
2.2
#include<stdio.h>
#include<math.h>
int main()
{
float f, x, y;
scanf("%f%f",&x,&y);
f=sqrt(pow(x,2)+pow(y,3));
printf("f=%.2f\n", f);
return 0;
}