Resposta :
[tex]\Large\boxed{\begin{array}{l}\sf f(x-1)=x^2-k\\\sf f(-2-1)=(-2)^2-k\\\sf f(-3)=4-k\\\sf 4-k=7\\\sf k=4-7\\\sf k=-3\end{array}}[/tex]
[tex]\Large\boxed{\begin{array}{l}\sf f(x-1)=x^2-k\\\sf f(-2-1)=(-2)^2-k\\\sf f(-3)=4-k\\\sf 4-k=7\\\sf k=4-7\\\sf k=-3\end{array}}[/tex]