P=1,5+1,5+1,5=4,5=4 1/2
#2
(1/10)^2+99/100=1/100+99/100=1
#3
8(1/2+1 1/4)=4+10=14(м)
1) За т. Виета
х1 = -2, х2 = -11
2) х²-0,5х-7,5=0
за т. Виета
х1 = -2,5, х2 = 3
3) х²-14х+49-2х²-11х-23=0
х²+25х-26=0
За т. Виета
х1 = -26
х2 = 1
30,(8) = 30 целых 8/9 = 278/9
- - - - - - - - - - - - - - - - - - - - - - - - -
а) 10% = 10/100 = 1/10
278/9 - 1/10 * 278/9 = 278/9 - 278/90 = 2780/90 - 278/90 = 2502/90 = 278/10 = 27 целых 8/10 = 27 целых 4/5
б) 62% = 62/100 = 31/50
278/9 - 31/50 * 278/9 = 278/9 - 8618/450 = 13900/450 - 8618/450 = 5282/450 = 2641/225 = 11 целых 166/225
в) 90% = 90/100 = 9/10
278/9 - 9/10 * 278/9 = 278/9 - 278/10 = 2780/90 - 2502/90 = 278/90 = 3 целых 8/90 = 3 целых 4/45
460-(750-550):10=440
1)750-550=200
2)200:10=20
3)460-20=440