In the function f(x) = 4(x2 − 6x + ____) + 20, what number belongs in the blank to complete the square?

Numerical Answers Expected!

Question

In the function f(x) = 4(x2 − 6x + ____) + 20, what number belongs in the blank to complete the square?

Numerical Answers Expected!

dancergirl45 · Answer

@welshfella please help

welshfella · Answer

the number in the blank has to be the square  of half the coefficient of  x

owikbenstan · Answer

Completing the square of a quadratic function is as follows $$(\frac{b}{2})^2$$ In this case, b is equal to -6x so your answer is $$(\frac{-6}{2})^2$$ or 9

dancergirl45 · Answer

Ya i was not sure if it was 9 or 4

dancergirl45 · Answer

@owikbenstan @welshfella are you sure its 9

owikbenstan · Answer

Make sure when you give your answer, you decide which format it should be in, either $$(x+3)^2 or (x-3)^2$$ - Hint it depends on what the sign of the middle term is.

welshfella · Answer

yes owik gave a perfectly good answer and explanation

dancergirl45 · Answer

I think i just put the number in the blank

welshfella · Answer

yes

dancergirl45 · Answer

ok thank you guys so much i am not sure who to give best response to

welshfella · Answer

well i gave a medal to owik and someone gave me one so thas ok.

dancergirl45 · Answer

I am already @welshfella fan so i will medal you and fan owik

welshfella · Answer

oh ok