290
b_(2)=3/2
q=b_(2):b_(1)=(3/2):(3/4)=2
q=b_(3)^b_(2)=3:(3/2)=2
b_(n)=b_(1)*q^(n-1)
192=(3/4)*2^(n-1)
2^(n-1)=256
2^(n-1)=2^(8)
n-1=8
[b]n=9[/b]
b_(1)=48
b_(2)=?
b_(3)=?
b_(4)=?
b_(5)=243
b_(n)=b_(1)*q^(n-1)
b_(5)=b_(1)*q^(4)
243=48*q^4
q^4=(243/48)
q^(4)=(81/16)
q=3/2 или q=-3/2
b_(2)=48*(3/2)=72 или b_(2)=48*(-3/2)=-72
b_(3)=72*(3/2)=108 или 108
b_(4)=108*(3/2)=162 или -162