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 July 19th, 2015, 04:56 AM #1 Newbie   Joined: Dec 2013 Posts: 28 Thanks: 0 write radical expression in simplest form the expression is $\sqrt{5x^{2}y}\sqrt{3y}$ these are my steps: $\sqrt{15x^{2}y^{2}} \left |x \right |\left | y \right |\sqrt{15}$ however in the book the answer is : $\left |x \right | y\sqrt{15}$ why are not the absolute value bars surrounding the y? Last edited by mick7; July 19th, 2015 at 05:00 AM.
July 19th, 2015, 08:41 AM   #2
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Quote:
 Originally Posted by mick7 the expression is $\sqrt{5x^{2}y}\sqrt{3y}$ these are my steps: $\sqrt{15x^{2}y^{2}} \left |x \right |\left | y \right |\sqrt{15}$ however in the book the answer is : $\left |x \right | y\sqrt{15}$ why are not the absolute value bars surrounding the y?
Your original expression contains $\displaystyle \sqrt{y}$. This means that y has to be positive, so absolute value bars aren't needed.

-Dan

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