If anyone can help me out with these problems I’d appreciate it.

What is the quadric regression equation that fits these data

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.

1.two more than the quotient of a number and 6 is equal to 7 use the c for the unknown number translate the sentence into an equation