<span>9^2х-1=1/27
(3^2)^(2x-1)=3^(-3)
3^(4x-2)=3^(-3)
4x-2=-3
4x=-3+2
4x=-1
x=-1/4
x=-0,25
Ответ:</span><span>x=-0,25</span>
469 делится на 7 =67
1139 делится на 17 = 67
1)
b1 = 27; b2 = 24
bn = b1+(n-1)d
bn = bn-1+d
d = b2-b1 = -3
b21 = 27-3*20 = -47
2)
c2 = -9; c3 = -5
d = c3-c2 = 4
c1 = c2-d = -13
Sn = n(2c1+d(n-1))/2
S8 = (-26+4(8-1))*8/2 = 8