Question

for the function w, w(9)=-7, and w(-7)=9. If y=w(x), what is the value of y when x=-7?

Answer 1

that question is already solved, here is the proof:
w(-7) = 9
which means that the function w in terms of -7 equals 9
the question is how much is the value of the function w(x) when x = -7, that is, again:
w(-7) = 9
w(x) = y
so the value of y is 9