Solve the equation below by completing the square and then solving for x.

x^2 + 14x + 24 = 0

A. x = 8 or x = 3
B. x = -12 or x = -2
C. x = 2 or x = -2
D. x = -2 or x = -5

Question

Solve the equation below by completing the square and then solving for x.

x^2 + 14x + 24 = 0

 		A.	x = 8 or x = 3
 		B.	x = -12 or x = -2
 		C.	x = 2 or x = -2
 		D.	x = -2 or x = -5

hippoharry · Answer

@Erak do i divide by 14?

erak · Answer

Take 14/2, then square that.

hippoharry · Answer

i got seven. do i then square that?

erak · Answer

Yeah then you do something where you add and subtract that number, like so:

x^2 + 14x + 49 + 24 - 49 = 0

Then move the original 24 and the -49 over:

x^2 + 14x + 49 = -24 + 49

Recognise the left side turns into a perfect square and simplify the right

(x+7)^2 = 25

Try the rest

hippoharry · Answer

x=-12 and x=-2

erak · Answer

yeah, because you get +5 and -5 when you square root the 25, and 7 subtracted from those numbers are -12 and -2