Solve x2 – 2x = 8 by completing the square. Show your work for full credit.

Question

anonymous · Answer

$$x ^{2}-2x-8=0$$
(x+2)(x-4)=0
x+2=0 x-4=0
x=-2 & x=4

anonymous · Answer

x2 – 2x +1 -1= 8
(x-1)2 -1 =8
(x-1)2 =9
x-1=+-3
x=4
x=-2

anonymous · Answer

my way is what you looking for @dmartinez130. @katlg87 solved it by factorizing

anonymous · Answer

$$x^{2}-2x=8$$
$$x^{2}-2x-8=0$$
$$x^{2}-4x+2x-8=0$$
x(x-4)+2(x-4)=0
(x+2) (x+4)
x=-2 OR x=4

campbell_st · Answer

rewrite the equation

$$x2 -2x = 8$$

the general form is 

$$ax^2 + bx + c$$

to complete the square add $$(\frac{b}{2})^2$$

to both sides

in you question add  (-2/2)^1 to both sides

$$x^2 -2x + 1 = 9$$

now factorise the left hand side

$$(x -1)^2 = 9 $$