View Compilation Error

0_0_32580673_23551.cpp:10:1: error: stray '\' in program
 cout<<(a+b)*(a-b)/4<<\n;
 ^
0_0_32580673_23551.cpp: In function 'int main()':
0_0_32580673_23551.cpp:10:23: error: 'n' was not declared in this scope
 cout<<(a+b)*(a-b)/4<<\n;
                       ^