Question 963738
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{{{(sqrt(-15))*(sqrt(-5))}}}<br>
The rule {{{(sqrt(a))*(sqrt(b))=sqrt(ab)}}} does NOT hold if both a and b are negative.<br>
{{{(sqrt(-15))*(sqrt(-5))=(i*sqrt(15))*(i*sqrt(5))=(i^2)*sqrt(75)=(-1)*sqrt(75)=-5sqrt(3)}}}<br>
ANSWER: {{{-5sqrt(3)}}}<br>