Question

A student is deriving the quadratic formula. Her first two steps are shown.

Answer 1

Answer:

factoring the binomial

Step-by-step explanation:

Answer 2

The polynomial in its standard form is:

$ax ^ 2 + bx + c$

The student's first step is:

$-c = ax ^ 2 + bx$

The student's second step is:

$-c = a (x ^ 2 + (\frac{b}{a}) x)$

The student's second step is to factor the remaining binomial on the right side of the equation.

In this case, the student made a common factor of the letter a.

Answer:

The sentence that best explains or justifies Step 2 is:

factoring the binomial