Answer:
Read explanation and apply it
Step-by-step explanation:
The vertex form of a quadratic equation is 
The general form of a quadratic equation is 
The factored form of a quadratic equation is 
The one which reveals the zeros of f(x) without needing to alter the equation is the factored form
.
When f(x)=0, we have 
The values of x are
and
.
I hope this guides you to choose the correct answer.