11. a. -2, b. 1.5 12. a. 1/10 b. 1.2 meters c. 0 by using the formula for finding slope of (y2-y1)/(x2-x1) so (2-2)/(30-20) gives 0/10 and since anything divided by 0 is 0 (also by looking at the line which is flat there is no obvious change), 13. y = - 10x + 35
