Please help! Variables!!

Answer:
-x^4, and (2√x)/x
Step-by-step explanation:
4. [tex]- \sqrt{ x^{8} } = - \sqrt{x^{4} *x^{4} } = -x^{4}[/tex]
x^8 = x*x*x*x*x*x*x*x = (x*x*x*x)(x*x*x*x) = (x^4)(x^4)
5.
[tex]\sqrt{\frac{4}{x} } = \frac{\sqrt{4} }{\sqrt{x} } = \frac{2}{\sqrt{x} } \\\\\\\frac{2}{\sqrt{x} } * \frac{\sqrt{x} }{\sqrt{x} } = \frac{2\sqrt{x} }{x}[/tex]