Question

how many zero pairs must be added to the function ( f(x) = x^2 - 10x - 4 ) in order to begin writing the function in vertex form?
( circ ) 4
( circ ) 10
( circ ) 21
( circ ) 25

Explanation:

Step1: Recall vertex form method

Vertex form uses completing the square.

Step2: Isolate x-terms

For $f(x)=x^2-10x-4$, focus on $x^2-10x$.

Step3: Find the constant for square

Take half of -10: $\frac{-10}{2}=-5$, square it: $(-5)^2=25$.

Step4: Identify zero pairs needed

To complete the square, we add and subtract 25 (a zero pair), so 25 zero pairs are added.

Answer:

25