Question

Simplify the given expression.


sqaure root -108 + sqaure root -27. Please help, cause I'm so lost..

Answer 1

\[\sqrt{-108}+\sqrt{-27}= (\sqrt{108}*i)+(\sqrt{27}*i)\]

Answer 2

it should be 6isquareroot6+3isquareroot3

Answer 3

you cant add radicals that arent the same

Answer 4

\[9i \sqrt{3}\]

Answer 5

earth citizen is correct i looked at my paper wrong sorry

Answer 6

do you understand the answer?

Answer 7

Me? Not really.

Answer 8

Do you want to?

Answer 9

Yes

Answer 10

ok, look at just the first term:\[\sqrt{-108}\]factor the number under the radical sign:\[\sqrt{-1\times2\times2\times3\times3\times3}\]we know that \[\sqrt{-1}=i\]so we can pull that out of the radical.
Also, whenever we see two factors the same under the radical that means we can pull out one copy:\[\sqrt{-1\times2\times2\times3\times3\times3}=\sqrt{2^2\times3^2\times(-1)\times3}=(2\times3)i\sqrt3\]\[=6i\sqrt3\]...

Answer 11

you can do the same with \[\sqrt{-27}=\sqrt{-1\times3\times3\times3}=\sqrt{-1\times3^2\times3}=3i\sqrt3\]adding the two together then gives\[\sqrt{-108}+\sqrt{-27}=6i\sqrt3+3i\sqrt3=9i\sqrt3\]I hope that help you understand the problem better.

Answer 12

Thank you so much!

Answer 13

welcome :)

Answer 14

thnx!