Question 652351
<pre>
square root of -15 multiplied by square root of -3 divided by square root of 5
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x = 5 or  -  4, as stated by the other person, is WRONG!   

The statement by the other person, ".....BUT, if you multiply a negative square root by another
negative square root, you get a positive!", is DEAD WRONG! As a result, his/her answer, 3, is WRONG!

{{{highlight(sqrt(- 15)sqrt(- 3)/sqrt(5))}}} 
{{{sqrt(- 1 * 3 * 5)sqrt(- 1 * 3)/sqrt(5)}}}
{{{sqrt(- 1)sqrt(3)sqrt(5)sqrt(- 1)sqrt(3)/sqrt(5)}}} ----- Applying {{{sqrt(m*n*o) = sqrt(m)sqrt(n)sqrt(o)}}}, {{{sqrt(m*n) = sqrt(m)sqrt(n)}}}
{{{i*sqrt(3)sqrt(5)i*sqrt(3)/sqrt(5)}}} ---- Changing {{{sqrt(- 1)}}} to i
{{{i*sqrt(3)cross(sqrt(5))i*sqrt(3)/cross(sqrt(5)) = i*sqrt(3)*i*sqrt(3) = (sqrt(3)i)^2 = 3i^2 = 3(  -  1) = highlight(  -  3)}}}</font></font></font></b></pre>