5. (a) suppose that a is countable. prove that if f : a + b is onto, then b is also countable. (b) prove the union of any two countably infinite sets is countably infinite. (c) prove the set of irrational numbers is uncountable.

"how does lena finally defeat the robots? ” this question will best be used to describe the story’s exposition. rising action. climax. falling action.

Omar is going on a road trip! the car rental company offers him two types of cars. each car has a fixed price, but he also needs to consider the cost of fuel. the first car costs $90 to rent, and because of its fuel consumption rate, there's an additional cost of s0.50 per kilometer driven.

Consider the proof. given: segment ab is parallel to line de. prove: what is the missing statement in step 5?