Simplify: 26 • -5

Giving brainliest^^

A) 130
B) 21
C) -105
D) -130

Umm.. just started this 2day and its not on my notes(p′︵‵。)

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.

2/3(-6y+9x) expand each expression using the distributive property