[tex] \sqrt{9 + 9 \times 8} - \sqrt{169 - 25} + 100 \times 0.18 = \sqrt{9 + 72} - \sqrt{144} + 18 = \sqrt{81} - 12 + 18 = 9 - 12 + 18 = - 3 + 18 = 15[/tex]
