Ican't seem to figure this question out. i've worked it out but i keep getting stuck

Compare the subtraction problems 6/8 - 5/8 = 1/8 and 6/9 - 7/9 = 1/9 why is the answer to the first problem positive and the answer to the second problem negative

What is the first quartile of this data set? 10, 11, 12, 15, 17, 19, 22, 24, 29, 33, 38 a. 12 b. 19 c. 29 d. 10

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?