Question

x^2+81=0 using square root property

Answer 1

To solve this you need to use complex numbers.

So \[\sqrt{-1}=i\]

\[x ^{2}+81=0\] So subtract 81 from both sides.\[x ^{2}=-81\]

Take the square root of both sides.\[(x ^{2})^{1/2}=(-81)^{1/2}\] \[x=\pm \sqrt{-81}\]\[x=\pm \sqrt{(-1)*(81)}\]\[x=\pm \sqrt{-1}*\sqrt{81}\]\[x=\pm9i\]

Answer 2

Thanks so much!!

Answer 3

Now try to do the other one on your own.