## Intermediate Algebra for College Students (7th Edition)

$-7|x^3|$
RECALL: (i) $\sqrt{a^2} = a$ when $a\ge0$ (ii) $\sqrt{a^2} = |a|$ when $a\lt0$ Use the rules above to obtain: $-\sqrt{49x^6}=-\sqrt{(7x^3)^2}=-7|x^3|$ (The absolute value has to be applied to $x^3$ to make its value always nonnegative).