[tex] \frac{x \times \sqrt{50} - {x}^{2} }{1 - x \times \sqrt{4.5} } = \frac{ \sqrt{2} \times \sqrt{50} - ( \sqrt{2} {)}^{2} }{1 - \sqrt{2} \times \sqrt{4.5} } = \frac{ \sqrt{100} - 2 }{1 - \sqrt{9} } = \frac{10 - 2}{1 - 3} = \frac{8}{ - 2} = 8 \div ( - 2) = - 4[/tex]
