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

665. б) S5=b1*(q^4–1)/(q–1)=(4*80)/(-4)=–80г) S5=b1*(q^4–1)/(q–1)=(-1/3*15)/(-3)==5/3д) b3=b1*q^2q^2=b3/b1=2q=/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=33667. S100=b1*(q^99–1)/(q–1)==(1*(-2)/(-2)=1S101=b1*(q^100–1)/(q–1)==(1*0)/(-2)=0669. a) S10=b1*(q^9–1)/(q–1)==(-1/36)*511)/1=-511/36б) S6=b1*(q^5–1)/(q–1)==(-1/27*242)/2=-121/27в) S10=b1*(q^9–1)/(q–1)==(-1/36*(-513)/(-3)=-4,75г) S6=b1*(q^5–1)/(q–1)==(-2/27*(-244)/(-4)=(488/27*(-4)==-122/27