398•0=0 name the property

Ineed with number 6 , explain how to get 1978

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76

The graph shows the decibel measure for sounds depending on how many times as intense they are as the threshold of sound. noise in a quiet room is 500 times as intense as the threshold of sound. what is the decibel measurement for the quiet room? 20 decibels28 decibels200 decibels280 decibels