[tex]1) \\ \\ a) \sqrt{2 \frac{7}{9} } = \sqrt{ \frac{2 \times 9 + 7}{9} } = \sqrt{ \frac{18 + 7}{9} } = \sqrt{ \frac{25}{9} } = \frac{ \sqrt{25} }{ \sqrt{9} } = \frac{5}{3} = 1 \frac{2}{3} [/tex]
[tex]b) \sqrt{6 \frac{1}{4} } = \sqrt{ \frac{6 \times 4 + 1}{4} } = \sqrt{ \frac{24 + 1}{4} } = \sqrt{ \frac{25}{4} } = \frac{ \sqrt{25} }{ \sqrt{4} } = \frac{5}{2} = 2 \frac{1}{2} [/tex]
[tex]2) \\ \\ a)2 \sqrt{49} - 3 \sqrt{25} = 2 \times 7 - 3 \times 5 = 14 - 15 = - 1 [/tex]
[tex]b)10 \sqrt{ \frac{81}{100} } = 10 \times \frac{ \sqrt{81} }{ \sqrt{100} } = 10 \times \frac{9}{10} = \frac{90}{10} = 9 [/tex]
