Mt bi ton gii trong na t A4 lun p ng ng yu cu ca B.Khng AM - GM, khng Cauchy - Schwarz, khng Jensen, khng bi ba bi 4, khng bin i tng ng max kh. Gii c vi dng l xong. Vy kh ch no vy mi ngi i?Xin ni trc nh, i hc bao gi cng rt hp dn v kch tnh ch khng phi k thi m ai cng c th dnh ti 9 im.Ai cng l bc s th bn c dm i m rut tha khng?Ai cng lm chnh tr gia th t nc c yn n?Ai cng lm cng an, b i th t nc ny c ch cho du khch i b thong th trn ng khng phi mang o chng n?Khng tm ti, khng lin tc tm ra ci mi th loi ngi mi ch l con vn i bng hai chn, bao gi tm ra c nh la tn?Khng mt cng nghin cu t ph, bao gi loi ngi c in nhn, c my tnh ngi y m Facebook?Cuc sng lun phi vt qua nhng th thch kh khn, bi l nhim v, quyn li v trch nhim ca loi ngi.Hy ci v bn thy mt bi ton kh v cm thy may mn khi nhn ra cch gii."Trong cuc i khng ai hon ho, nhng phi lun hng n s hon ho" -on Tr Dng.P/s: Li gii caNguyn Th Duy tm hiu thm v li gii, xem:https://www.youtube.com/watch?v=plvaB0XaTDM