Ребят, решите пж, срочно! Только то, что обведено и закрашено!!!

665. б) S5=b1*(q^4–1)/(q–1)=(4*80)/(-4)=–80 г) S5=b1*(q^4–1)/(q–1)=(-1/3*15)/(-3)= =5/3 д) b3=b1*q^2 q^2=b3/b1=2 q=/2 (корень из 2) S5=b1*(q^4–1)/(q–1)=(1*3)/(/2–1)= =3:(/2–1) 666. S6=b1*(q^5–1)/(q–1)= =48*(-33/32):(-3/2)= =(48*(-33)*2)/(32*(-3))=528/16=33 667. S100=b1*(q^99–1)/(q–1)= =(1*(-2)/(-2)=1 S101=b1*(q^100–1)/(q–1)= =(1*0)/(-2)=0 669. a) S10=b1*(q^9–1)/(q–1)= =(-1/36)*511)/1=-511/36 б) S6=b1*(q^5–1)/(q–1)= =(-1/27*242)/2=-121/27 в) S10=b1*(q^9–1)/(q–1)= =(-1/36*(-513)/(-3)=-4,75 г) S6=b1*(q^5–1)/(q–1)= =(-2/27*(-244)/(-4)=(488/27*(-4)= =-122/27