Help please! this thing hard!!

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.

Solve this equation using substitution. {4x + y = −2} {4x + 6y = 44}

What additional information could be used to prove abc =mqr using sas? check all that apply.