# write radical expression in simplest form

#### mick7

the expression is

$$\displaystyle \sqrt{5x^{2}y}\sqrt{3y}$$

these are my steps:

$$\displaystyle \sqrt{15x^{2}y^{2}} \left |x \right |\left | y \right |\sqrt{15}$$

however in the book the answer is :

$$\displaystyle \left |x \right | y\sqrt{15}$$

why are not the absolute value bars surrounding the y? :help:

Last edited:

#### topsquark

Math Team
the expression is

$$\displaystyle \sqrt{5x^{2}y}\sqrt{3y}$$

these are my steps:

$$\displaystyle \sqrt{15x^{2}y^{2}} \left |x \right |\left | y \right |\sqrt{15}$$

however in the book the answer is :

$$\displaystyle \left |x \right | y\sqrt{15}$$

why are not the absolute value bars surrounding the y? :help:
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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