1)2,8-3,1-4,9+4,2=9,4
1. 2.8-3,1=-0,3
2. -0,3-4,9=-5,2
3. -5,2+4,2=1
2)4(4с-3)-(10с+8)=16с-12-10с-8=6с-20=6*5/6-20=6/1*5/6=15
1) 14х2 - 5х - 1 = 0
D = 25 + 56 = 81 Кор.D = 9
x1 = 5 + 9/ 28 = 0,5
x2 = 5 - 9/ 28 = - 1/7
2) 2x2 + x + 67 = 0
D = 1 - 536 = - 535
Розв'язку немає
3) 2p2 + 7p - 30 = 0
D = 49 + 240 = 289 Kor.D = 17
p1 = -7 + 17/ 4 = 2,5
p2 = -7 - 17/ 4 = - 6
4) y2 - 3y - 5 = 0
D = 9 + 20 = 29 Kor.D = kor z 29
x = 3 + - kor z 29 / 2
5) 5x2 - 11x + 2 = 0
D= 121 - 40 = 81
kor D = 9
x1 = 11 + 9 / 10 = 2
x2 = 11 - 9 / 10 = 0,2
6) 9x2 - 30y + 25 = 0
D = 900 - 900 = 0
x = 30 / 18 = 5/3
Ф(-3)=(-3-6)/(-3+4)=-9/1=-9
Ф(6)=(6-6)/(6+4)=0/10=0
Ф(0)=(0-6)/(0+4)=-6/4=-1.5
B1=1/3 q=1/3 bn=1/729
bn=b1*q^n-1
1/3*(1/3)^n-1=(1/3)^n=1/729=(1/3)^6
n=6