1. 3(z-2)-z=4z-20
3z-6-z=4z-20
-2z=-14
z=7
2. the slope = (8-5)/(4-10)=-1/2
3. the equation is
(y-8)/(x-3)=3
y-8=3x-9
y=3x-1
4. the slope of a horizontal line is 0
5. to graph the required equation, you can put any values to x , then find the corresponding value of y, for example put x=0, y=2*0+3=3, you can put two different values to x then you will get 2 different sets of coordinates, then you jot the coordinates on the graph paper and you can plot out the line! hope this help you:)