Select a $$ notation for each expression. Provide answer in the blank and show work

below the problem.

a$.2+4+8+16+$dots$+2^n$

ANSWER

b$.(1000)2^n+4^n$

ANSWER

c$.4n+3nlo{g}_{2}n+2lo{g}_{2}n,$ ANSWER.

d$.$ ANSWER