Х^2-10х+25+30=x+25
x^2-11x+30=0
D=(-11)^2-4*30=1
x1=(11-1):2=5
x2=(11+1):2=6
1
1/2х=4
х=4:1/2
х=4*2/1*1
х=8
2
-3/4у=6
у=6:(-3/4)
у=-6*4/1*3
у=-8
3
-1/3к=-1/6
к=-1/6:(-1/3)
к=1*3/6*1
к=0,5
4
1/2х=-12/3
х=-5*2/3*1
х=-3 1/3
5
-8/9а=-1 7/9
а=-1 7/9:(-8/9)
а=16*9/9*8
а=2
-1/6*4,2-(3/8)=-1/6*4,2+3/8=-1/6*4(целых)2/10+3/8=-1/6*42/10+3/8=-7/10*3/8=56+30/80=86/80=1,075
Решение
<span>b1= - 64 i q = -1/2.
Sn = [b</span>₁(1 - q^n)] / (1 - q)
bn = b₁ * q^(n - 1)
b₆ = (- 64) * (- 1/2)⁵ = 64/32 = 2
S₅ = [(- 64) * (1 - (-1/2)⁶] / [1 - (- 1/2)] = [- 64*(1 - 1/64)] / (1 + 1/2) =
= [- 64 * (63/64)] / (3/2) = (- 63 * 2) / 3 = - 21 * 2 = - 42