Question

3x√8x -4√x^3 +3x√72x x=2

Answer 1

\[\Large 3x \sqrt {8x} -4 \sqrt {x^3} +3x \sqrt {72x}\]when x=2? If that's it, replace all the x's with 2, and simplify.

Answer 2

Could you work it out for me, please? I am really bad at math.

Answer 3

I'll plug in the 2's for you, i'm sure you can simplify it somewhat from here\[\Large 3*2 \sqrt {8*2} -4 \sqrt {2^3} +3*2 \sqrt {72*2}\]

Answer 4

6√16 -4√8 +6√144 right?

Answer 5

Correct. Now two of those square roots are perfect squares which are easy to simplify...

Answer 6

6√4 -4√8 +6√12 ?

Answer 7

The square root of 16 is equal to 4, not the square root of 4. The square root of 144 is equal to 12, not the square root of 12.
\[\large \sqrt {16} = 4\]\[\large \sqrt {144} =12\]

Answer 8

How would you write that with the equation?

Answer 9

Replace the sqrt of 16 with 4, and the sqrt of 144 with 12...remember that the numbers in front are multiplying like so \[\Large 6*\sqrt{16} -4 \sqrt 8 +6 *\sqrt {144 } = \]

Answer 10

So it would be 6*4 -4√8 +6*12 ?

Answer 11

Yes. So simplify that as much as you can, then we'll deal with the last sqrt.

Answer 12

Remember you can change the order... 6*4 -4√8 +6*12 = 6*4 + 6*12 - 4√8

Answer 13

24 -4√8 +72

Answer 14

96 -4√8

Answer 15

Now simplify the sqrt 8 like so.... since 8 is 4*2
\[\Large 96 -4 \sqrt 8 = 96 - 4 \sqrt { 4*2}\]
\[\Large 96 - 4* \sqrt 4 \sqrt 2\]

Answer 16

Would it make it 218.81?

Answer 17

No. You're keeping exact values. Simplify what i just posted.

Answer 18

Not sure if I know how to do that. Sorry.

Answer 19

You just did it with the other square roots above, now try it with this. Simplify everything that you can, leave any square roots that you can't. \[\Large 96 - 4* \sqrt 4 * \sqrt 2\]

Answer 20

96-4 * 2√2*√2

Answer 21

The square root of 4 is 2, so replace the sqrt of 4 with 2...\[\Large 96 - 4* \sqrt 4 * \sqrt 2 = \]
\[\Large 96 - 4* 2* \sqrt 2\]Now you can finish simplifying. There's only the 4 and 2 to multiply together.

Answer 22

And you're done :)

Answer 23

Thank you so much!

Answer 24

Welcome :)