Question

the difference between the fourth and the third term of a geometric sequence is 75/8

Answer 1

a1=a  

a3=ar2  

a4=ar3

a4−a3=758a1  

8(a4−a3)=75a1  

8(ar3−ar2)=75a  

8ar3−8ar2−75a=0  

a(2r−5)(4r2+6r+15)

r = 5/2