For the first one use the slope formula: 
So for you that would look like this:
For number 2, in order for a slope to be 0, it has to be a completely horizontal line with no steepness whatsoever. That can ONLY happen with lines that are "y=some constant with no x". So that answer has to be y = -5. For that last one, we have to use the slope-intercept form of a line and use the point they give us along with the slope to find the y-intercept, or the "b". That looks like this for us:
so b= 5/6. So our equation, fitting the slope and y intercept back in, gives us 
So for you that would look like this:
For number 2, in order for a slope to be 0, it has to be a completely horizontal line with no steepness whatsoever. That can ONLY happen with lines that are "y=some constant with no x". So that answer has to be y = -5. For that last one, we have to use the slope-intercept form of a line and use the point they give us along with the slope to find the y-intercept, or the "b". That looks like this for us: