Answer:
[tex]10(x - a) \\ [/tex]
Step-by-step explanation:
[tex] \sqrt{ {x}^{2} - {a}^{2} } \sqrt{ \frac{10}{a + x} } \\ = {( \sqrt{ {x}^{2} - {a}^{2} } \sqrt{ \frac{10}{a + x} })}^{2} \\ = ({x }^{2} - {a}^{2} ) \times ( \frac{10}{a + x} ) \\ = (x - a)(x + a) \times \frac{10}{a + x} \\ = (x - a) \times 10 \\ = 10(x - a) \\ [/tex]
