Question

Aflați primul termen al progresie geometrice cu termeni pozitivi b1, b2, 27,81

Answer 1

b3= 27

b4= 81

De aici scoatem ratia q

b4=b3*q => q= $\frac{b4}{b3}$ = $\frac{81}{27}$ = 3

b2= $\frac{b3}{q}$ = $\frac{27}{3}$ = 9

b1 = $\frac{b2}{q}$ = $\frac{9}{3}$ = 3

Deci termenii sunt 3, 9, 27, 81