SOLUTION: find all real values of x such that f(x)=0: {{{f(x)=x^2-9}}} please help thanks

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Question 52851: find all real values of x such that f(x)=0:
f%28x%29=x%5E2-9
please help
thanks
Answer by rchill(405) About Me  (Show Source):
You can put this solution on YOUR website!
We rewrite the equation to 0=x%5E2-9. Add 9 to both sides to get 9=x%5E2. Now take the square root of both sides and we see that x=3 or x=-3.