Which expression is equivalent to 4 • 4 • 4 • 4 • 4 • 4 • 4 • 4

Ineed asap.i cant understand this question i need someone to me right away

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.

Identify the polynomial. a2b - cd3 a.monomial b.binomial c.trinomial d.four-term polynomial e.five-term polynomial