Question

Determine r if an is geometric progression and a4-a2=18 and a5-a3=36

Answer 1

Step-by-step explanation:

a2=ar

a4=ar^3

a5=ar^4

a3=ar^2

now ((a4-a2) /(a5-a3) )=18/36

(ar^3-ar)/(ar^4-ar^2)=1/2

(r^2-1)/r(r^2-1)=1/2

1/r=1/2

r=2