To find the slope when you are given two point your can use y2 - y1over x2-x1 Ex: on number four 2 would be your x1 and -5 would be your y1 so the -1 would be your x2 and 7 would be your y2
And for the ones that give you slope you would use y= mx+b Ex: on number one your equation would be 4=3/4(8)+b