Hey can someone be nice enough to help me

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?

Powerful women's group has claimed that men and women differ in attitudes about sexual discrimination. a group of 50 men (group 1) and 40 women (group 2) were asked if they thought sexual discrimination is a problem in the united states. of those sampled, 11 of the men and 19 of the women did believe that sexual discrimination is a problem. if the p-value turns out to be 0.035 (which is not the real value in this data set), then at = 0.05, you should fail to reject h0. at = 0.04, you should reject h0. at = 0.03, you should reject h0. none of these would be a correct statement.

Me! i really need to get this right before 9. prove the divisibility of 7^6+7^5-7^4 by 11. use factoring so you get a number times 11. just tell me the number. i need this done asap