Dont answer this question if you dont know the answer

Perform the indicated operation. 8/a - 6/a + 7/a

D(5, 7). e(4,3), and f(8, 2) form the vertices of a triangle. what is mzdef? oa. 30° ob. 45° oc. 60° od 90°

Jonathan can type 20 documents in 40 minutes ,and susan can type it in 30 minutes and jack can type it in 24 minutes working together ,how much time will it is take them type the same document