Respuesta :

Answer:

The answer is the option B

[tex]-4,-14[/tex]

Step-by-step explanation:

we know that

The formula to solve a quadratic equation of the form [tex]ax^{2} +bx+c=0[/tex] is equal to

[tex]x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}[/tex]

in this problem we have

[tex]x^{2}+18x+81=25[/tex]  

[tex]x^{2}+18x+56=0[/tex]  

so

[tex]a=1\\b=18\\c=56[/tex]

substitute in the formula

[tex]x=\frac{-18(+/-)\sqrt{18^{2}-4(1)(56)}} {2(1)}[/tex]

[tex]x=\frac{-18(+/-)\sqrt{100}} {2}[/tex]

[tex]x=\frac{-18(+/-)10} {2}[/tex]

[tex]x1=\frac{-18+10} {2}=-4[/tex]

[tex]x2=\frac{-18-10} {2}=-14[/tex]

Answer:

The correct option is B. -4 , -14  

Step-by-step explanation:

The equation is given to be : x² + 18x + 81 = 25

We need to find the roots of this given equation

⇒ x² + 18x + 81 = 25

⇒ x² + 18x + 81 - 25 = 0

⇒ x² + 18x + 56 = 0

⇒ x² + 14x + 4x + 56 = 0

⇒ x( x + 14) + 4( x + 14) = 0

⇒ (x + 14) · (x + 4) = 0

⇒ x = -14 or x = -4

Therefore, The correct option is B. -4 , -14