Application of binomial theorem and pascal's triangle

Question

I am having difficulties understanding, and subsequently solving this problem:

"Suppose that b is an integer with b ≥ 7. Use the binomial theorem and the appropriate row of Pascal’s triangle to find the base-b expansion of (11)4 b [that is, the fourth power of the number (11)b in base-b notation]."

I am familiar with the binomial theorem as well as pascal's triangle, but I am confused how to properly apply them to this problem.

Thank you for any insight you can provide.

Answer 1

Recall that $11$ in base $b$ notation means $b+1$, and note that $$(b+1)^4=b^4+4b^3+6b^2+4b+1.$$