1.Find the sum of the series -1+1+5+13+39+.....to n terms2.If the ratio of the seventh term from the beginning and end in the binomial expansion (cube root of 2 +1/cube root of 3)^n is 1:6 , find n Thank you sir for your previous answer !
1.Find the sum of the series -1+1+5+13+39+.....to n terms
2.If the ratio of the seventh term from the beginning and end in the binomial expansion (cube root of 2 +1/cube root of 3)^n is 1:6 , find n
Thank you sir for your previous answer !











