/images/1041385860215607387/1255996224906067968/toan-cau-cu-tinh-tong-luyen-tap-sinh-khai-thuy-chuong-497-bien-co.txt?ex=667f2923&is=667dd7a3&hm=8640a01e957df0563e2f1d1303efe9b0603d82969aa7f75ec64704626eae74c2&