What are the coordinate pairs of x-9y=12

Which of the functions graphed below has a removable discontinuity?

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b

If a line is defined by the equation y = 5x + 2, what is the slope?