Please help me

If 7x=9y, y/z = 7/5 , then x/z = (a) 2/7 (b) 7/9 (c) 9/5 (d) 9/7 (e) 5/9

The equations 2x-5y = -5 11x-5y = 15 9x+ 5y = 5 and 14x+ 5y = -5 are shown on the graph below. which system of equations has a solution of approximately (-0.6. 0.8)?

At saturday nights football game there were 18 less fans than half the fans at friday nights game.there were "x" fans at friday's game.write an expression to represent the number of fans at saturday's game. *** urgent***