Verified answer

[tex]2 - 3 \sqrt{ \frac{25}{36} } = 2 - 3 \sqrt{ \frac{ {5}^{2} }{ {6}^{2} } } = 2 - \frac{3 \times 5}{6} = \\ 2 - \frac{5}{2} = 2 - 2.5 = - 0.5[/tex]