Final answer:
The value of y, where y=w(x), when x=-7 is given directly as w(-7)=9. Therefore, y is 9.
Step-by-step explanation:
The question asks for the value of y when x=-7 for the function w, given that w(9)=-7, and w(-7)=9. From the information, if y=w(x), then when x=-7, the value of y is simply what is assigned by the function w at that point, which is given as 9.
Therefore, y=w(-7)=9. This result implies that the function w takes the input -7 and maps it to 9, therefore y, which represents the value of the function at any input x, is 9 when x equals -7.