.Perhaps, everyone knows that Greece is literally a Museum under the open sky. In every town of this country, as in great and small, has everything. As a rule, attractions in Greece, many tourists visiting, starting with the capital city Athens. First of all, being here, worth to visit the Acropolis – the most famous monument of architecture of ancient times. Near it stands the partially restored temple of Poseidon. It is washed by the waters of the Aegean sea, which adds into the whole picture more charm and ancient essence. The next point in the tour, every tourist must be the quarter of Plaka.A country which in my lifetime has gone through many changes of government, religions and other life cycles, is Greece. Crete, the attractions of this island can each visitor to tell part of the story, having dipped it in the distant past. One of those places where still reigns the spirit of past centuries, is considered the city of gortyn, which was once the most important on the island. Here is preserved ancient streets and squares, still surrounded by the walls of temples of various gods, and even houses inhabited by local residents modern, saturated with the atmosphere of the Dorian era in which they were built. Of course, speaking about sacred places in Greece, located in Crete, one cannot lose sight of Kera kardiotissa convent. It is located near the village of Kerala and dates back to the 13th century. Within its walls is stored the most valuable in the world the icon of the virgin Kardiotissa, which is able to heal all the sick, to perform miracles and help those who suffer.
1) (х²-88)²-9х²=0 (х²-88)²-(3х)²=0 (х²-88-3х)(х²-88+3х²)=0 произведение множителей равно нулю тогда и только тогда, когда хотя бы один из множителей равен 0: х²-3х-88=0 или х²+3х-88=0 по Т. Виета: Х3+Х4=-3 Х1+Х2=3 Х3·Х4=-88 Х1·Х2=-88 Х1=11,Х2=-8 Х3=-11,Х4=8 ответ: -11;-8;8;11 2) (х²+21)²-100х²=0 (х²+21-10х)(х²+21+10х)=0 х²-10х+21=0 или х²+10х+21=0 Х1+Х2=10 Х3+Х4=-10 Х1·Х2=21 Х3·Х4= 21 Х1=7,Х2=3 Х3=-3,Х4=-7 ответ: -7;-3;3;7. 3) х³-7х²-4х+28=0 сгруппируем: (х³-7х²)-(4х-28)=0 х²(х-7)-4(х-7)=0 (х-7)(х²-4)=0 (х-7)(х-2)(х+2)=0 х-7=0 или х-2=0 или х+2=0 х=7 х=2 х=-2 ответ:-2;2;7. 4) 4у³+28у²-у-7=0 (4у³+28у²)-(у+7)=0 4у²(у+7)-(у+7)=0 (у+7)(4у²-1)=0 (у+7)(2у-1)(2у+1)=0 у+7=0 или 2у-1=0 или 2у+1=0 у=-7 2у=1 2у=-1 у=1/2 у=-1/2 ответ: -7;-1/2; 1/2
(х²-88)²-9х²=0
(х²-88)²-(3х)²=0
(х²-88-3х)(х²-88+3х²)=0
произведение множителей равно нулю тогда и только тогда, когда хотя бы один из множителей равен 0:
х²-3х-88=0 или х²+3х-88=0
по Т. Виета: Х3+Х4=-3
Х1+Х2=3 Х3·Х4=-88
Х1·Х2=-88
Х1=11,Х2=-8 Х3=-11,Х4=8
ответ: -11;-8;8;11
2)
(х²+21)²-100х²=0
(х²+21-10х)(х²+21+10х)=0
х²-10х+21=0 или х²+10х+21=0
Х1+Х2=10 Х3+Х4=-10
Х1·Х2=21 Х3·Х4= 21
Х1=7,Х2=3 Х3=-3,Х4=-7
ответ: -7;-3;3;7.
3)
х³-7х²-4х+28=0
сгруппируем:
(х³-7х²)-(4х-28)=0
х²(х-7)-4(х-7)=0
(х-7)(х²-4)=0
(х-7)(х-2)(х+2)=0
х-7=0 или х-2=0 или х+2=0
х=7 х=2 х=-2
ответ:-2;2;7.
4)
4у³+28у²-у-7=0
(4у³+28у²)-(у+7)=0
4у²(у+7)-(у+7)=0
(у+7)(4у²-1)=0
(у+7)(2у-1)(2у+1)=0
у+7=0 или 2у-1=0 или 2у+1=0
у=-7 2у=1 2у=-1
у=1/2 у=-1/2
ответ: -7;-1/2; 1/2