Which value for x makes the sectence true? 1/27 x equals 1/9

Can someone me out here and the tell me the greatest common factor

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?

20.ju inces. which ordered pair is a viable solution if x represents the number of books he orders and y represents the total weight of the books, in ounces? (-3,-18) (-0.5, -3) (0,0) (0.5, 3)