Question

Solve the equation by taking square roots:

4(x+2)^2=64

Answer 1

=2(x+2)=8
x+2=4
x=2

Answer 2

That's not really right.

Answer 3

sqrt{4(x+2)^2} = 4(x+2)
sqrt{64} = 8, -8
4x + 8 = -8
x = 4
4x+8 = 8

x = 0

x = 0, 4

Answer 4

cause sqr(x^2)=|x|?

Answer 5

So I distribute the ^2 ?

Answer 6

Actually sorry angela, that is correct.

Answer 7

Wait, no. I was right originally.

Answer 8

The answer on the answer sheet says -6, 2. Don't over think it.

Answer 9

C'mon Polpak..make up ur mind :P

Answer 10

\[4(x+2)^2 = 64\]\[\implies (x+2)^2 =16 \]\[\implies \sqrt{(x+2)^2} = \sqrt{16}\]\[\implies |x+2| = 4\]\[\implies x+2 = 4 \text{ OR } x+2 = -4\]
Then solve both of those equations to find what your possible x's are

Answer 11

Okay, but how do I get -6 ?

Answer 12

x+2 = -4

Subtract 2 from both sides

Answer 13

Fist divide both sides by 4, then take the square root of both sides\[(x + 2)^2 = 16\]

x+ 2 = 4 and x + 2 = -4
Then finish solving.

Answer 14

Okay. Thank you so much. I didn't divide by the 4 first, so that's where I got screwed up. Thanks.

Answer 15

You can always divide by the 2 after you take the square root if you didn't divide by the 4 originally.

Answer 16

Okay, thank you.