Respuesta :

Answer:

Step-by-step explanation:

rewrite 9-6x+[tex]x^{2}[/tex] as [tex]x^{2}[/tex]-6x+9.  (this step isn't necessary, but it's easier when the bigger term is in front)

There's two ways: using the quadratic formula, or just doing it in your head (for simple ones)

For the simple way:

think about what numbers not only multiply to equal c (represented by 9 in this case) but also add to equal -6 (represents b in this problem).  There are two numbers for this problem that work: -3 and -3.  So you would write the factored form as (x-3)(x-3)

Quadratic formula:

The formula is [tex]\frac{-b}{2a}[/tex] ±[tex]\frac{\sqrt{b^{2}-4ac } }{2a}[/tex]

This formula works for equations in the form of a[tex]x^{2}[/tex]+bx+c.

Substitute in the values to get:

[tex]\frac{6}{2} +\frac{\sqrt{-6^{2} -4(1)(9)} }{2}[/tex]

simplify:

3±[tex]\frac{\sqrt{36-36} }{2}[/tex]

3±[tex]\frac{0}{2}[/tex]

the answer is 3, which is the x-intercept.  Write that as (x-3)(x-3)