b2-b2=b1*q-b1=b1(q-1)=-3/4
b4-b2=b1*q^3-b1*q=b1q(q^2-1)=3/16
делю второе на первое
b1q(q-1)(q+1)/(b1(q-1))=q(q+1)=3/16:(-3/4)=-1/4
q^2+q+1/4=0
D=1-1=0
q= -1/2
b1=-3/4:(q-1)=-3/4:(-1/2-1)=-3/4:(-3/2)=1/2
b1=1/2;q=-1/2
b2-b2=b1*q-b1=b1(q-1)=-3/4
b4-b2=b1*q^3-b1*q=b1q(q^2-1)=3/16
делю второе на первое
b1q(q-1)(q+1)/(b1(q-1))=q(q+1)=3/16:(-3/4)=-1/4
q^2+q+1/4=0
D=1-1=0
q= -1/2
b1=-3/4:(q-1)=-3/4:(-1/2-1)=-3/4:(-3/2)=1/2
b1=1/2;q=-1/2