Solve by completing the square and then use the square root method to solve. x2 - 4x - 32 = 0

Question

btaylor · Answer

$$x^{2}-4x+4=32+4=36$$$$(x-2)^{2}=36$$$$x-2=\pm \sqrt{36} = \pm 6$$$$x=2 \pm 6$$ so x=8 or x=-4

campbell_st · Answer

start by rewriting the equation to 

x^2 - 4x = 32

to complete the square you need ( -4/2)^2 = 4

add 4 to both sides

x^2 - 4x + 4 = 32 +4

factor the left hand side

$$(x - 2)^2 = 36$$
 
take the square root of both sides

$$x - 2 = \pm \sqrt{36}$$

add 2 to both sides

$$x = 2 \pm 6$$

x = 8, -4