What is the rate of change

1. what is the measure of ∠abc? what is the measure of ∠abd?

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

Do more republicans (group a) than democrats (group b) favor a bill to make it easier for someone to own a firearm? two hundred republicans and two hundred democrats were asked if they favored a bill that made it easier for someone to own a firearm. how would we write the alternative hypothesis?