Question

what number needs to be added to each
$x^{2}+2x-8=0$
○ a. 1
○ b. 2
○ c. 8
○ d. 4

Explanation:

Step1: Isolate x terms

$x^2 + 2x = 8$

Step2: Find the constant to complete the square

Take half of 2: $\frac{2}{2}=1$, square it: $1^2=1$

Step3: Verify adding the constant

Adding 1 to both sides gives $x^2+2x+1=8+1$, which is $(x+1)^2=9$, a perfect square trinomial.

Answer:

a. 1