explain well and easy step. thank u$.$

Solve the following recurrence using the Back Substitution method, and check

your results with the Master Theorem Show ALL your work including at least three sub$-$stitutions before you move to k steps, and computed summations. No credit will be given if students don$$t show all their work in detail.

T $($n$)=16$T $($n$/2)+$ n$^3+$ n $+1$