What is the equivalent expression of -1/7-5/16

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.

List the sides of δrst in in ascending order (shortest to longest) if: m∠r =x+28°, m∠s = 2x+16°, and m∠t = x+12°

Asystem of equations has 1 solution. if 4x-y=5 is one of the equations , which could be the other equation ?