Question

select the correct answer. solve the equation by completing the square. $x^2 - 18x + 58 = 0$ a. $x = 9 pm sqrt{139}$ b. $x = 9 pm sqrt{23}$ c. $x = -9 pm sqrt{23}$ d. $x = -9 pm sqrt{139}$

Explanation:

Step1: Move constant to right

$x^2 - 18x = -58$

Step2: Complete the square

$x^2 -18x + 81 = -58 +81$
$(x-9)^2 =23$

Step3: Solve for x

$x-9 = \pm\sqrt{23}$
$x=9\pm\sqrt{23}$

Answer:

B. $x = 9 \pm \sqrt{23}$