The operation ○ is defined by the equation x ○ y = (x-y)/(x+y), where y ≠ -x. If 3 ○ y = 5 ○ 4, then y =
~$\frac{1}{9}$~
~$\frac{4}{15}$~
~$\frac{5}{12}$~
~$\frac{12}{5}$~
~$\frac{15}{4}$~
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