Apex help 10 points!

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 lm, find the measure of (award brainliest)

20 points - ! gia decides to buy square tiles to cover her kitchen floor. the tiles are 18” square tiles and cost $3.85 each. how much will it cost to tile her kitchen if the measurements are 11’ x 12’?