Cos(180 +x)=-cos(x) use sum and difference Formula

Agiven line has the equation 2x + 12y = −1. what is the equation, in slope-intercept form, of the line that is perpendicular to the given line and passes through the point (0, 9)? y = ( )x + 9

Issof claims that the scale factor is 1/2. which statement about his claim is correct

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