Question

HELP?!?!?!?!?!?!?

Solve by using the perfect squares method.



x^2 + 4x + 4 = 0



A.
2


B.
4


C.


–4


D.


–2

Answer 1

http://openstudy.com/study#/updates/53626c58e4b0a83d8e0efe7a

Answer 2

can you help me?

Answer 3

@AkashdeepDeb

Answer 4

@paki

Answer 5

x^2 + 4x + 4 = 0

Well to find the values of x when that whole expression equals zero.
You need to know some rules.

\[a^2 + b^2 + 2ab = (a+b)(a+b) = (a+b)^2\]\[a^2+b^2-2ab = (a-b)(a-b) = (a-b)^2\]
If you notice, both the equations there ^ are perfect squares, which IS what we want! :D

So x^2 + 4x + 4 = 0
is written in the first form.

Thus,\[x^2 + 2(2)(x) + 2^2 = 0 ~~~~~~~~~~(Written~~in~~the~~proper~~format)\] \[(x+2)(x+2) = (x+2)^2 = 0\]

Thus, for (x+2)^2 to be equal to zero.

x has to be -2,-2 [which are the two solutions or roots]

Answer 6

omg thank you!!! but i thought the formula was a^2+bx+c=0?

Answer 7

sorry ax^2+bx+c=0

Answer 8

@amistre64

Answer 9

Yes, that IS the formula of a quadratic equation!
And this is also a quadratic equation.
The rules that I wrote up there were just identities,

Say, if I have

x^2 - 6x + 9 = 0

You can use one of those rules [the 2nd rule] and write it like:

x^2 - 2(3)(x) + (3)^2 = (x-3)^2 = 0
Thus x = 3,3

Answer 10

thank you!!!

Answer 11

:)