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Mathematics 14 Online
OpenStudy (jpes2193):

Solve Analytically. See comments

OpenStudy (jpes2193):

\[\sqrt{4x+13}+1=2x\]

OpenStudy (jpes2193):

a small step by step would be appreciated.

OpenStudy (dtan5457):

Was afk, sorry. Anyways, a step by step it is. 1. Subtract the 1 to the other side \[\sqrt{4x+13}=2x-1\] Square both sides to get rid of the radical \[4x+13=4x^2-4x+1\] Get like terms on one side \[4x^2-8x-12=0\] Factor, quadratic formula, whatever works for you.

OpenStudy (dtan5457):

Once you factor it, check for extraneous solutions (because there is one)

OpenStudy (jpes2193):

you know i really just need to go with my gut on starting these problems..

OpenStudy (dtan5457):

Haha, you got it now?

OpenStudy (jpes2193):

yea checking for extraneous would be plugging the answers back into the original equation right

OpenStudy (dtan5457):

Yep, an extraneous solution would not make the equation true

OpenStudy (jpes2193):

okay let me plug away at this an see what I get

OpenStudy (dtan5457):

Any luck?

OpenStudy (jpes2193):

I got -1,3 and both make the equation =0

OpenStudy (dtan5457):

Hmm, want to show some work so I can find a mistake?

OpenStudy (jpes2193):

give me a sec and I'll have it up.

OpenStudy (dtan5457):

No problem, take your time. Props to you for trying on each problem.

OpenStudy (jpes2193):

WAIT?!?! wouldn't 4 be the extraneous solution because 4 does not = 0

OpenStudy (dtan5457):

Oh wait a minute, I think I see your problem.

OpenStudy (dtan5457):

You don't plug -1,3 into the quadratic, but into the original equation.

OpenStudy (dtan5457):

If you plug it into the quadratic, both are gonna look true since you factored it directly from the quadratic. Plug -1,3 into the original question

OpenStudy (jpes2193):

light bulb.

OpenStudy (dtan5457):

Lol, which one is extraneous. ?

OpenStudy (jpes2193):

-1

OpenStudy (dtan5457):

bingo

OpenStudy (dtan5457):

your answer is 3 :)

OpenStudy (jpes2193):

Thank you :)

OpenStudy (dtan5457):

yw

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