Question

I'm needing help trying to answer 3 problems, can anyone do a videochat with me on this stupid problems

Answer 1

I can maybe help you through twiddla by using graphs and stuff. But first, let me see the question(s) so I can tell you if I'm qualified to help.

Answer 2

this site is full of Helpers! :)

Answer 3

\[\sqrt{2x+4}=\sqrt{x+3}+1\]

Answer 4

Hmm... I do think I can do this. Alright.

Answer 5

I can do this too!

Answer 6

i gott stuck when you square the other side......

Answer 7

Let's do it, then. :P http://www.twiddla.com/584304

Answer 8

the square of 1 is 1.

Answer 9

x = 6

Answer 10

\[\sqrt{2x+4}=\sqrt{x+3}+1\]
\[(\sqrt{2x+4})^2=(\sqrt{x+3}+1)^2\]
\[2x+4=(\sqrt{x+3}+1)(\sqrt{x+3}+1)\]
\[2x+4=(x+3)+2\sqrt{x+3}+1\]
\[2x-x+4-3-1=2\sqrt{x+3}\]
\[3x=2\sqrt{x+3}\]
\[(3x)^2=(\sqrt{x+3})^2\]
9x^2=x+3

Answer 11

oops my 2 disappeared!

Answer 12

nope, itz wrong myininaya

Answer 13

\[9x^2=4(x+3)\]

Answer 14

yes i know my i said my 2 disappeared lol

Answer 15

\[x ^{2} - 4x - 12 = 0\]

Answer 16

ok you are right and i also did 2x+x instead of 2x-x
you are right

Answer 17

Which factors to (x-6)(x+2)

Answer 18

We got it all solved in Twiddla. Lol.

Great work, dude.

Answer 19

Is there a convention about only taking the positive root? I.e. do we include the x= -2 as a solution?

Answer 20

@Phi: You really go to MIT?

Answer 21

-2 is not a solution since left hand side would not = right hand side
sqrt{2(-2)+4}=0
sqrt{-2+3}+1=1+1=2

Answer 22

:O
Weird! How did I not catch that when I checked? Thanks, myininaya.

Answer 23

OK, but in the second equation
\[\sqrt{-2+3}= \sqrt{1}= \pm1\]
So, if we choose -1 we would get -1+1= 0
But I think people only use the positive root??

Answer 24

use only positive
the symbol means principal square root (only positive outcome)