Q:

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 + 18xFactor 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 – 27What is the missing value in the last step?

Accepted Solution

A:
Answer:3Step-by-step explanation:f(x) = 18x + 3x^2f(x) = Β 3x^2+18xFactor out a 3 Β  Β  Β = 3(x^2 +6x)Take the coefficient of x, divide by 2 and then square6/2 = 3 3^2 =9Remember the 3 out side 3*9 =27 so we are really adding 273(x^2+6x+9) -3*9The number inside the parentheses added to x is b/2 Β or 6/23(x+3)^2 -27