Question

How do I get from 2a+a+sqrt(3a^2)=20 to.... a=8.453?

Answer 1

How did you arrive at that answer?

Answer 2

wolframalpha.com

Answer 3

are you sure you plugged it in correctly?

Answer 4

I entered the equation exactly how it here.

Answer 5

Then you must've typed it here wrong. That is not the correct answer.

Answer 6

Double check

Answer 7

http://www.wolframalpha.com/input/?i=2a%2Ba%2B+sqrt%283a%5E2%29%3D20 are you able to see this, my friend?

Answer 8

\[2a+a+\sqrt(3a^2)=20\]

Answer 9

Yes, that correct.

Answer 10

It doesn't say the answer is 8.453

Answer 11

It does, in the solution: a=-10/3(sqrt(3)-3).

Answer 12

That comes out to approximately 4.2265

Answer 13

Not 8.453

Answer 14

You're right I made a mistake, my answer is two times 4.2265.

Answer 15

OK i will show you how to do the work correctly.

Answer 16

I am still wondering how I get there though.

Answer 17

\[3a+\sqrt(3a^2)=20\]
\[a(3+\sqrt(3))=20\]
\[a=\frac{20}{(3+\sqrt(3))}\]

Answer 18

From here we rationalize the denominator

Answer 19

I am confused in the second step.

Answer 20

\[\frac{20}{3+\sqrt(3)} * \frac{3-\sqrt(3)}{3-\sqrt(3)}\]

Answer 21

In the second step i simply factored out an a because \[\sqrt(a^2)=a\]

Answer 22

so it would be \[3a+a \sqrt(3)\]

Answer 23

Then you can factor out an a here, see?

Answer 24

okay, i see now thank you very much !

Answer 25

Do you know how to rationalize the denominator?

Answer 26

You must do that to get to the final answer

Answer 27

I do, i need to try it to make sure i get the mechanics of it.

Answer 28

The numberator should be 60-20sqrt(3), correct? And I am having difficulties with the denominator? Could you help please?

Answer 29

Nevermind, I figured it out, thank you.