1. Is the set closed or not closed under the operation? integers under addition

2. Is the set closed or not closed under the operation?
positive integers under multiplication

3. Is the set closed or not closed under the operation?
negative integers under multiplication

The swimming pool is open when the high temperature is higher than 20∘c. lainey tried to swim on monday and thursday (which was 3 days later). the pool was open on monday, but it was closed on thursday. the high temperature was 30∘c on monday, but decreased at a constant rate in the next 3 days. write an inequality to determine the rate of temperature decrease in degrees celsius per day, d, from monday to thursday.

How do i solve uniform motion problems?

Which pair of numbers is relatively prime? a. 105 and 128 b. 130 and 273 c. 205 and 350 d. 273 and 333