trong mf voi he truc oxy,cho tam giac ABC noi tiep duong tron tam K.goi H la hinh chieu cua A tren BC (H thuoc doan BC). duong phan giac trong cua goc BAC co phuong trinh x+1=0.tim toa do cac dinh B va C biet K(5/8;-1/4), H(-13/5;-1/5) va B co hoanh do am