Which expression can be used to model the phrase “the sum of three and a number”?

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.

If 1/√5+1/√5+1=p+q√r , find the values of p, q and r

What is the image of c for a 90° counterclockwise rotation about a? (3, 7) (-1, 3) (7, 3)