Question

Complete the square x^2+6x-16=0

Answer 1

X=2 and x= -8
x^2+6x-16=0
1) Move the constant (-16) to the right of the equal sign: x^2+6x = 16 (becomes positive)
2) Make the left side a perfect trinomial by doing half of 6 (3) then squaring it (9). Add 9 to the 16: x^2+6x+9= 16+9. 
3) Factor the left side, then find the sum of the right side: (x+3)^2 = 25
4) Take the square root of both sides: x+3 =(+/-) 5 (remember it's both positive & negative).
The equation will look like x+3= - 5 and x+3=5

5) solve the two equations: x= -8 and x=2

When you put the x-values back into the problem, it should come out 0. 

Hope this helps

Answer 2

Let's solve your equation step-by-step:
x^2+6x-16=0
Factor the left side of the equation:(x-2)(x+8)=0
Set factors equal to 0: x-2=0 or x+8=0, x=2 or x=-8
Your answer is x=2 or x=-8, doesn't matter which, both are correct.
Hope this helps!:)