How to rewrite 3/4 with the denominator 12

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?

Find the value of x for which line a is parallel to line b

Complete each sentence with the correct form of the verb ser or estar to say where the following people are from or where they are right now claudia y maria en méxico