Tn=ar^n-1. Hence, T2=ar^2-1=6. So 6=ar^1.therefore r=6/a. Having eastablish this.moving to the next statement T4=ar^4-1=54. Hence 54=ar^3. Recall r=6/a. Therefore 54=a[6/a]^3.moving forward 54=216a/a^3.simplifying 54=216/a^2. 54a^2=216, a^2=216/54. a^2=4,a=2.recall,a=6/a,therefore,r=6/a,r=3.having known r and a T5=2×3^4.T5=2×71=142.oops
