Write the equation of the quadratic function with roots -10 and -8 and a vertex at (-9, -3).Answer

f(x) = 3x2 + 54x − 120

f(x) = 3x2 - 54x + 240

f(x) = 3x2 + 54x + 120

f(x) = 3x2 + 54x + 240

Question

Write the equation of the quadratic function with roots -10 and -8 and a vertex at (-9, -3).Answer
		
f(x) = 3x2 + 54x − 120
		
f(x) = 3x2 - 54x + 240
		
f(x) = 3x2 + 54x + 120
		
f(x) = 3x2 + 54x + 240

anonymous · Answer

@ktnguyen1 Help?

anonymous · Answer

@MiaKitty help?

anonymous · Answer

I would just plug in -9 into x, and see if it equals  -3.

anonymous · Answer

@MiaKitty I got f(x) = 3x2 + 54x − 120

anonymous · Answer

Wait just a sec! ) I think I can write down a formula to help you.

anonymous · Answer

-b/2a will give you your x, plug x into the formula to find your y.

anonymous · Answer

What do you think it is? The one you gave me was wrong. Try using the formula, and plug x into x and find if y equals -3, and that is your equation. :)