T(n) = T(n/7) +T(3n/4) + 8n
     = [T(n/7^2)  + T(n(3/4)/7) + 8n/7] +
       [T(n(3/4)/7)  + T(n(3/4)^2) + (3/4)8n]
     = [T(n/7^3)  + T(n(3/4)/7^2) + 8n/7^2] +
       [T((3/4)n/7^2)  + T(n(3/4)^2/7) + (3/4)8n/7] +
         [T(n(3/4)/7^2)  + T(n(3/4)^2/7) + (3/4)8n/7] +
         [T(3/4)^2n/7)  + T((3/4)^3 n) + (3/4)^2 8n]
     =   T( n/7^3      ) +
        3T( n(3/4)/7^2 ) +
        3T( n(3/4)^2/7 ) +
         T( n(3/4)^3   ) +
        8n[ 1/7^2 + 2(3/4)/7 + (3/4)^2 ]