we get a2 and a5 so a2=a1(r)^(2-1)=a1(r)^1=a1r a5=a1(r)^(5-1)=a1(r)^4
also remember that [tex] \frac{x^m}{x^n}=x^{m-n} [/tex] so [tex] \frac{a_5}{a_2}= \frac{a_1r^4}{a_1r^1} =r^{4-1}=r^3= \frac{512}{-8}=-64 [/tex] so r^3=-64 cube root r=-4 so
a2=a1r=-8 a2=a1(-4)=-8 divide both sides by -4 a1=2
