View Compilation Error

0_0_29822592_11156.cpp: In function 'int main()':
0_0_29822592_11156.cpp:6:14: error: expected primary-expression before ',' token
  int a=(x+y)/,b=(x-y)/2;
              ^
0_0_29822592_11156.cpp:7:18: error: 'b' was not declared in this scope
  printf("%d\n",a*b);
                  ^