[latex]a_1=2\ a_2=a_1*q=2*q\ a_3=a_1*q^2=2*q^2\ \ b_1=b_4-2*d=30-2*d\ b_2=b+4-d=30-d\ b+3=30\ \a_2=b_1=>2*q=30-2*d\ a_3=b_2=>2*q^2=30-d\ \ left {{{2*q=30-2*d} atop{2*q^2=30-d}} ight\ q=frac{30-2d}{2}\ 2*(frac{30-2d}{2})^2=30-d\ frac{(30-2d)^2}{2}=30-d/*2\ 900-120d+4d^2=60-2d\ 4d^2-118d+840=0/:2\ 2d^2-59d+420=0\ Delta=b^2-4ac=9-59)^2-4*2*420=3481-3360=121\ sqrt{Delta}=+11, -11\ d_1=frac{-b-sqrtDelta}{2a}=frac{59-11}{4}=frac{48}{4}=12\ d_2=frac{-b+sqrtDelta}{2a}=frac{59+11}{4}=frac{70}{4}=17,5\ q_1=frac{[latex]q_1=frac{30-2d_1}{2}=frac{30-24}{2}=frac{6}{2}=3\ q_2=frac{30-2d_2}{2}=frac{30-35}{2}=-frac{5}{2}=-2,5<0 nie bierzemy pod uwage\ \ a_1=2\ a_2=a_1*q_1=2*3=6=b_1\ a_3=a_1*q_1^2=2*3^2=2*9=18=b_2\ b_3=30[/latex]
