688 4
-4 172
-28
28
0 -8
8
0
как то так
1 1/11, 5 2/3, 21 1/2, 22 2/5, 16 1/4.
8) 3/(х-5)^1/2=4; умножим все на (х-5)^1/2;
4*(х-5)^1/2=3;
(х-5)^1/2=3/4;
х-5=9/16;
х=5+9/16; то есть ответ г) 5 целых 9/16;
9) (х+3)/(3-х)=(х-3)/(3+х)-90/(х^2-9);
90/(х-3)(х+3)=(х-3)/(х+3)-(х+3)/(-(х-3));
90/(х-3)(х+3)=((х-3)(х-3)+(х+3)(х+3))/(х+3)(х-3); умножим на (х-3)(х+3);
90=х^2-6х+9+х^2+6х+9;
2х^2=90-18; 2х^2= 72; х^2=36; х=6 или -6;
значит ответ в) +-6.
10) 9878:11=898;
Ответ в) 8;
11) А) 8, 16, 32.
0+5=5
1+4=5
2+3=5
Теперь при помощи полученных чисел составим 3-значные
500
140
410
230
320
Итого, 5 чисел
Ответ:
1) Jane never visits picture galleries, does she?
2) We have no pets at home, do we?
3) There is no castle in our town, is there ?
4) Jack can't play water polo, can he?
5) There was a river near our country house, wasn't there?
6) Our trip was very interesting, wasn't it?
7) There was no forest there, was there?
8) We never play badminton, do we?