Please answer, it's very important ​

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

Given a: b and b: c, find a: b: c. write the ratio in simplest form. a: b=6: 10 and b: c=21: 33

Your best friend told you that last week scientists disco y that las vegas is responsible for abrupt climate changes. which do you think is best way to research that recent discovery? an encyclopedia usgs internet site a book in the library your best friend’s parents for your ! ❤️