Question

Pleeeeeeeease helppppppppppppppppp I don't understand

Answer 1

Answer: A) -5

Explanation:

$x^{2} -6x+9=(x-3)(x-3)=(x-3)^{2} \\\\f(x)=(x+2)^{2} \\f(x+a)=[(x+a)+2]^{2} =(x+a+2)^{2}\\\\(x+a+2)^{2}=(x-3)^{2}\\x+a+2=x-3\\x-x+a=-2-3\\a=-5$

I think that's how you do it?