to get the slope, find a spot on the graph and then go 1 to the right and read how much the graph went up or down.
on 5) you see it did neither, so m=0
when the graph goes up, m is positive, when it goes down, m is negative.
so on graph 1, you have 2 dots.
you go 2 right, and 4 down. when the dots are not 1 apart (counting going right) then divide by the steps you went right.
4 divided by 2 is 2.
-> graph went down, slope for 1) is m = -2
graph 2) you go 2 right and 2 up, 2/2 = 1. you went up, so m is positive and m = 1 for this graph.
3) is undefined because it doesn't go anywhere when you go right, it's 100% vertical
4) m = -5 because you went 1 right and 5 down
5) you go 6 right between the dots and 4 down. m is negative because it went down, not up. so m = -(4/6)