24/35-(z+13/35)=9/35
24/35 - (z + 13/35) = 9/35 z + 13/35 = 24/35 - 9/35 z + 13/35 = 15/35 z = 15/35 - 13/35 z = 2/35
24/35-9/35=15/35 15/35-13/35=2/35 Z=2/35