... Cõu 10 Coi c l bin, cũn a v b l tham s Ta cú: P = f (c) = GV: Ngụ Quang Võn 28 2016c 9a 6b + + ữ ab c b a Su tm v biờn son B ễN THI THPT QG - CU 8, 9, 10 2016 9a 6b 2016c 9a 6b 2016 9. 2 ... - 40t = t ( t - 10) ( t + 2) = t = 10 91 Bng bng bin thi n, ta thy f ( t ) t giỏ tr nh nht ti t = 10 v f ( 10) = 106 Kt lun P = f ( 10) = 91 t c x = , y = z = 106 18 ( thi th Violet) Cõu ... GV: Ngụ Quang Võn 16 Su tm v biờn son B ễN THI THPT QG - CU 8, 9, 10 61 + 11137 61 11137 (t / m); x = (l ) 18 18 61 + 11137 s: x = + ; x = 18 Cõu 10 Vi a, b, c , ta cú Vi 3a = 4b suy x = =>...