Prove a ≡ b (mod n) and b ≡ a (mod n) if and only if a= - b or b​

Which rational number could be graphed between -4 and -5

In need of in the diagram, ∠abc is a right angle. ∠dbc = 30°27'40". find the measure of ∠abd.

Suppose a store sells an average of 80 cases of soda per day. assume that each case contains 24 cans of soda and that the store is open 10 hours per day. find the average number of soda that the store sells per hour.