Question

Which of the following is an equivalent equation obtained by completing the square of the expression below? x^2+6x−8=0 A (x+3)^2=8 B (x+3)^2=17 C (x+3)^2=1 D x^2+6x+6=14

Answer 1

Answer:

Solving the equation $x^2+6x-8=0$ by completing the square method we get $\mathbf{(x+3)^2=17}$

Option B is correct option.

Step-by-step explanation:

We need to solve the equation $x^2+6x-8=0$ by completing the square method.

For completing the square method: we need to follow: $a^2+2ab+b^2=(a+b)^2$

We are given:

$x^2+6x-8=0$

Solving by completing the square

$x^2+2(x)(?)+(?)^2-8=0$

We need to find ? in our case ? is 3 because 2*3= 6 and our middle term is 6x i,e 2(x)(3)=6x.

So, adding and subtracting (3)^2

$x^2+2(x)(3)+(3)^2-8-(3)^2=0\\(x+3)^2-8-9=0\\(x+3)^2-17=0\\(x+3)^2=17$

So, solving the equation $x^2+6x-8=0$ by completing the square method we get $\mathbf{(x+3)^2=17}$

Option B is correct option.