1) since its pairs your working with what you do is y2-y1 and x2-x1 so to start its 9-(-2) which equals 11 then -4-(-3) which equals -1, 11/-1 is -11 I hope this is helpful . . .
2) to start its y=mx+b so since your slope is 2 and your pair is (0,-3) the equation would be -3=2(0)+b since 2(0) equals 0 your left with -3=0+b subtract 0 over answers b=-3