Question

simplify √3/(4√10)

Answer 1

i got as far as √30/40
??

Answer 2

what am i doing wrong?

Answer 3

Since you are not supposed to keep a radical in the denominator, you need to multiply by the radical in the denominator to get rid of it. So..\[\sqrt{3}\div(4\sqrt{10}) \] You need to multiply by \[\sqrt{10}/\sqrt{10}\] \[\sqrt{30}/40 \] is correct but you need to simplify the radical.

Answer 4

uhm... do i expand √30?

Answer 5

No I looked at the radical again and \[\sqrt{30}\] cannot be simplified so your answer should be correct.

Answer 6

cause the answer at the back of the book says √30/4 :s

Answer 7

In order to simplify radicals you would have to think of factors that would be perfect squares(i.e. 4,9,16, etc) but there are no factors of 30 that is a perfect square..

Answer 8

In my humble opinion, I think the book made a mistake. I also think the final answer should be \[\sqrt{30}\over 40\]

Answer 9

I agree with George

Answer 10

though i would love to see some algebra magic to turn it to \(\large\frac{\sqrt {30}}{4}\) -__-

Answer 11

I got this guys. Watch this magic. (works if the problem was written incorrectly)

Answer 12

okay there's also another question where the book may have made a mistake.

I'm asked to simplify 2√27+3√128-5√63-3√12

and i got -39√7
the book said its -9√7

is that the books mistake? or mine?

Answer 13

\[\sqrt{3}/4\sqrt{10} = {\sqrt{3} \over 4} \cdot {\sqrt{10}}={\sqrt{30} \over 4}\]

Answer 14

ahh the magic i wanted to see! mwahaha

Answer 15

oh wow! thanks kinggeorge! :)

Answer 16

but why woudl the book right it ambiguously as \(\sqrt 3 / 4 \sqrt 10\) -___-

Answer 17

waiit.... lgbasallote brings up a good point...
its √30/4

not √30/4√10

...

Answer 18

For the first problem, is it written as\[\sqrt{3}/4\sqrt{10} \]or as \[\sqrt{3}/(4\sqrt{10}) ?\]


Then, for that second problem, are you sure you wrote that correctly? I'm not getting anything near what you or the book is getting.

Answer 19

the first problem the back of the book gives me the answer √30/4

Answer 20

I would then assume it was at least meant to be written as \[{\sqrt{3}\over4}\sqrt{10} ={\sqrt{30} \over 4}\]

Answer 21

oh okay!
so about the other equation lemme type out what i got

Answer 22

2√(27)+3√(128)-5√(63)-3√(12)
= 2√(9x3) + 3√(4x7)-5√(9x7)-3√(4x3)
=2x3√(3)+3x2√(7)-5x9√(7)-3x2√(3)
=6√(3) + 6√(7) - 45√(7) - 6√(3)
= 6√(7)-45√(7)
=-39√(7)

Answer 23

back of the book said its -9√(7)

Answer 24

Wait wait wait... Is it \(\sqrt{128}\)? Or is it \(\sqrt{28}\)?

Answer 25

sorry i meant √28

Answer 26

I see your problem. The book is correct. Your mistake was with the term \(5\sqrt{63}\).\[5\sqrt{63}=5\sqrt{9\cdot 7}\]\[=5\sqrt{9}\sqrt{7}\]\[=5\cdot 3 \sqrt{7}=15\sqrt{7}\]Not \(45\sqrt{7}\)

Answer 27

OOOOOH now i see it. i should have triple checked my answer.
thank you !

Answer 28

You're welcome.

Answer 29

also would you mind helping me with another question?

Answer 30

nvm lol ! i got it

Answer 31

good job :)