... th nht lm c 10 (cv), 10h ngi th hai lm c 10 x (cv) y 29 1 1 u+v = u= x + y = 10 ta cú phng trỡnh t n ph ta cú (tha) 10 ì1 + 10 ì1 = 10 u + 10v = v = 15 y x suy x = 10 ; y = 15 Cõu ... AOD S AFB R 10 AD = ữ = AB 2R R 10 ữ 10 ữ = = 36 18 ữ ữ B http://violet.vn/nguyenthienhuongvp77 S AFB = 18 R : S ADO = R = R 18 5 S GIO DC V O TO K THI TUYN SINH LP 10 THPT TP. NNG ... giỏc ABC vuụng ti A, AH l ng cao, nờn: BC = 62 + 82 = 10 (nh lớ Pytago) v BC.AH= AB AC AH = AB AC 6.8 = = 4,8 ( cm ) BC 10 AB2=BC BH BH= 62 :10= 3,6(cm) b) b1) * Vỡ ba cung AB, BC, CD bng nhau,...