Step-by-step explanation:
The given function is :
[tex]f(x)=x^2-5x+ 5[/tex]
(a) To find f(9), put x = 9 in the above expression.
[tex]f(9)=9^2-5(9)+ 5=41[/tex]
(b) To find f(x+7), put x = x+7 in the above expression.
[tex]f(x+7)=(x+7)^2-5(x+7)+ 5\\\\=x^2+14x+49-5x-35+5\\\\=x^2+9x+19[/tex]
(c) To find f(-x), put x = -x in the above expression.
[tex]f(-x)=(-x)^2-5(-x)+ 5\\\\=x^2+5x+5[/tex]
Hence, this is the required solution.