Main.cc: In function ‘int main()’:
Main.cc:18:34: error: ‘y’ was not declared in this scope
float tongtien = A * X + B * y;
^
Main.cc:10:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &A);
~~~~~^~~~~~~~~~
Main.cc:12:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &B);
~~~~~^~~~~~~~~~
Main.cc:14:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%f", &X);
~~~~~^~~~~~~~~~
Main.cc:16:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%f", &Y);
~~~~~^~~~~~~~~~