Question

Complete the square to solve the equation below check all that apply x^2+8x-2=18

Answer 1

x^2+8x-2=18

x^2+8x-2-18= 18-18

x^2+8x-20= 0

(x-2)(x+10)=0

x-2= 0 , x+10=0

x-2+2= 0+2, x+10-10= 0-10

x=2 , x=-10

Answers are x= 2 -B, x=-10 -A.

Answer 2

Answer:

Option A and B

Step-by-step explanation:

Given : Quadratic equation $x^2+8x-2=18$

To find : Complete the square to solve the equation below check all that apply ?

Solution :

Re-write, $x^2+8x-2=18$

$x^2+8x-20=0$

Applying quadratic formula,

$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

Here, a=1 , b=8, c=-20

$x=\frac{-8\pm\sqrt{8^2-4(1)(-20)}}{2(1)}$

$x=\frac{-8\pm\sqrt{64+80}}{2}$

$x=\frac{-8\pm\sqrt{144}}{2}$

$x=\frac{-8\pm12}{2}$

$x=-4\pm6$

$x=-4+6,-4-6$

$x=2,-10$

The solution of the equation is x=2,-10.

Therefore, Option A,B satisfy the equation.