C\u00e2u 15:<\/b>\u00a0N\u1ebfu 21998<\/sup>\u00a0– 21997<\/sup>\u00a0– 21996<\/sup>\u00a0+ 21995<\/sup>\u00a0= k.21995<\/sup>\u00a0th\u00ec gi\u00e1 tr\u1ecb c\u1ee7a k l\u00e0<\/p>\n A.1\u00a0\u00a0\u00a0B.2 \u00a0\u00a0\u00a0C.3 \u00a0\u00a0\u00a0D. 4.<\/p>\n C\u00e2u 16:<\/b>\u00a0Cho a,b,x l\u00e0 c\u00e1c s\u1ed1 d\u01b0\u01a1ng th\u1ecfa m\u00e3n (2a)2b<\/sup>\u00a0= ab<\/sup>.xb<\/sup>\u00a0. Khi \u0111\u00f3 x b\u1eb1ng<\/p>\n A.2 \u00a0\u00a0\u00a0B.a \u00a0\u00a0\u00a0C. 2a\u00a0\u00a0\u00a0D. 4a.<\/p>\n C\u00e2u 17:<\/b>\u00a0Trong ph\u00f2ng th\u00ed nghi\u1ec7m, kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a 50 gi\u1ecdt m\u00e1u c\u00e2n \u0111\u01b0\u1ee3c l\u00e0 0,532 gam. Bi\u1ebft r\u1eb1ng kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang c\u1ee7a m\u00e1u l\u00e0 1060kg\/m3<\/sup>\u00a0v\u00e0 c\u00e1c gi\u1ecdt m\u00e1u \u0111\u1ec1u l\u00e0 h\u00ecnh c\u1ea7u c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng b\u1eb1ng nhau.T\u00ednh \u0111\u01b0\u1eddng k\u00ednh c\u1ee7a gi\u1ecdt m\u00e1u.<\/p>\n A.1,34mm\u00a0\u00a0\u00a0B.4,93mm\u00a0\u00a0\u00a0C.2,39mm\u00a0\u00a0\u00a0D. 2,68mm.<\/p>\n C\u00e2u 18:<\/b>\u00a0T\u00ednh s\u1ed1 nguy\u00ean n l\u1edbn nh\u1ea5t th\u1ecfa m\u00e3n n200<\/sup>\u00a0< 5300<\/sup>\u00a0.<\/p>\n A.10 \u00a0\u00a0\u00a0B.11\u00a0\u00a0\u00a0C.12\u00a0\u00a0\u00a0D.13.<\/p>\n C\u00e2u 19:<\/b>\u00a0Gi\u1ea3 s\u1eed a l\u00e0 s\u1ed1 th\u1ecfa m\u00e3n a + a-1<\/sup>\u00a0= 4 .T\u00cdnh gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c a4<\/sup>\u00a0+ a-4<\/sup>.<\/p>\n A.164\u00a0\u00a0\u00a0B.172\u00a0\u00a0\u00a0C.192\u00a0\u00a0\u00a0D.194.<\/p>\n C\u00e2u 20:<\/b>\u00a0Cho<\/p>\n <\/p>\n Gi\u1eefa x v\u00e0 y c\u00f3 h\u1ec7 th\u1ee9c n\u00e0o sau \u0111\u00e2y?<\/p>\n <\/p>\n H\u01b0\u1edbng d\u1eabn gi\u1ea3i v\u00e0 \u0110\u00e1p \u00e1n<\/b><\/p>\n C\u00e2u 15:<\/b><\/p>\n 21998<\/sup>\u00a0– 21997<\/sup> – 21996<\/sup>\u00a0+ 21995<\/sup>\u00a0= 21995<\/sup>(23<\/sup>\u00a0– 22<\/sup>\u00a0– 2 + 1) = 3.21995<\/sup>\u00a0= k.21995<\/sup>\u00a0=> k = 3<\/p>\n C\u00e2u 16:<\/b><\/p>\n (2a)2b<\/sup>\u00a0= ab<\/sup>.xb<\/sup>\u00a0=> (4a2<\/sup>)b<\/sup>\u00a0= (ax)b<\/sup>\u00a0=> 4a2<\/sup>\u00a0= ax => x = 4a<\/p>\n C\u00e2u 17:<\/b><\/p>\n Th\u1ec3 t\u00edch c\u1ee7a m\u1ed7i gi\u1ecdt m\u00e1u<\/p>\n <\/p>\n Ta c\u00f3<\/p>\n <\/p>\n (r l\u00e0 b\u00e1n k\u00ednh m\u1ed7i gi\u1ecdt m\u00e1u) n\u00ean<\/p>\n <\/p>\n C\u00e2u 18:<\/b><\/p>\n Ta t\u00ecm n trong c\u00e1c s\u1ed1 nguy\u00ean d\u01b0\u01a1ng. Khi \u0111\u00f3<\/p>\n n200<\/sup>\u00a0< 5300<\/sup>\u00a0<=> (n2<\/sup>)100<\/sup>\u00a0< (53<\/sup>)100<\/sup>\u00a0<=> n2<\/sup>\u00a0< 53<\/sup>\u00a0= 125 <=> n < \u221a125 \u2248 11,18<\/p>\n Ta th\u1ea5y s\u1ed1 nguy\u00ean d\u01b0\u01a1ng n l\u1edbn nh\u1ea5t th\u1ecfa m\u00e3n l\u00e0 n = 11<\/p>\n C\u00e2u 19:<\/b><\/p>\n a + a-1<\/sup>\u00a0= 4 => 16 = (a + a-1<\/sup>)2<\/sup>\u00a0= a2<\/sup>\u00a0+ 2 + a-2<\/sup>\u00a0=> 14 = a2<\/sup>\u00a0+ a-2<\/sup><\/p>\n => 196 = (a2<\/sup>\u00a0+ a-2<\/sup>)2<\/sup>\u00a0= a4<\/sup>\u00a0+ 2 + a-4<\/sup>\u00a0=> a4<\/sup>\u00a0+ a-4<\/sup>\u00a0= 194<\/p>\n C\u00e2u 20:<\/b><\/p>\n T\u1eeb gi\u1ea3 thi\u1ebft ta c\u00f3<\/p>\n <\/p>\n M\u1eb7t kh\u00e1c<\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" C\u00e2u 15:\u00a0N\u1ebfu 21998\u00a0– 21997\u00a0– 21996\u00a0+ 21995\u00a0= k.21995\u00a0th\u00ec gi\u00e1 tr\u1ecb c\u1ee7a k l\u00e0 A.1\u00a0\u00a0\u00a0B.2 \u00a0\u00a0\u00a0C.3 \u00a0\u00a0\u00a0D. 4. C\u00e2u 16:\u00a0Cho a,b,x l\u00e0 c\u00e1c s\u1ed1 d\u01b0\u01a1ng th\u1ecfa m\u00e3n (2a)2b\u00a0= ab.xb\u00a0. Khi \u0111\u00f3 x b\u1eb1ng A.2 \u00a0\u00a0\u00a0B.a \u00a0\u00a0\u00a0C. 2a\u00a0\u00a0\u00a0D. 4a. C\u00e2u 17:\u00a0Trong ph\u00f2ng th\u00ed nghi\u1ec7m, kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a 50 gi\u1ecdt m\u00e1u c\u00e2n \u0111\u01b0\u1ee3c l\u00e0 0,532 gam. Bi\u1ebft r\u1eb1ng kh\u1ed1i […]<\/p>\n","protected":false},"author":3,"featured_media":27624,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"tdm_status":"","tdm_grid_status":""},"categories":[157],"tags":[1447,1446],"yoast_head":"\n\n\n
\n 15-C<\/td>\n 16-D<\/td>\n 17-A<\/td>\n 18-B<\/td>\n 19-D<\/td>\n 20-A<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n