Question

The steps in writing f(x) = 18x + 3x2 in vertex form are shown, but a value is missing in the last step. Write the function in standard form. f(x) = 3x2 + 18x Factor a out of the first two terms. f(x) = 3(x2 + 6x) Form a perfect square trinomial. f(x) = 3(x2 + 6x + 9) – 3(9) Write the trinomial as a binomial squared. f(x) = 3(x + ______)2 – 27 What is the missing value in the last step?

Answer 1

option A

Explanation:

took the course :)

Answer 2

The missing value is 3.
The standard form of the equation will be f(x) = 3(x+3)² - 27.

Perfect square trinomial should have the form
a²+2ab+b²
3 is solved by extracting the square root of 9. You can also look at it by dividing the middle term 6 by 2.