Answer:
part a: -40 < x < 140
part b: open circles on both -40 and 140 with an arrow from each pointing inward. (towards zero). the solutions represent temperatures that will keep the gas in liquid form.
part c: it will freeze because -49 is less than -40, and therefore not a solution to the inequality.
Step-by-step explanation
a. x must be greater than -40 and less than 140 as outlined in the problem. so x > -40 and x < 140
b. open circles are non inclusive, and we do not include -40 or 140 because the gas will not be a liquid at those temps.