Please can y’all help me on this???

Identify an equation in point slope form for the line perpendicular to y=3x+5 that passes through (4,-1)

The volume of a cube is 8 in to the 3rd power. how long is each side?

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.