Question

dau coroana!!!!!!
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Answer 1

Răspuns:

$b) \frac{7 \sqrt{6} }{12} \div ( - \frac{21 \sqrt{3} }{8} ) = \\ = \frac{7 \sqrt{6} }{12} \times ( - \frac{8}{21 \sqrt{3} } ) = \\ = \frac{ \sqrt{2} }{3} \times - \frac {2}{3} = - \frac{2 \sqrt{2} }{9}$

$d)( \frac{11 \sqrt{6} }{4} - \frac{2 \sqrt{96} }{3} ) \div \frac{ \sqrt{3} }{9} = \\ = ( \frac{11 \sqrt{6} }{4} - \frac{2 \sqrt{96} }{3} ) \times \frac{9}{ \sqrt{3} } = \\ = \frac{99 \sqrt{6} }{4 \sqrt{3} } - \frac{18 \sqrt{96} }{3 \sqrt{3} } = \\ = \frac{99 \sqrt{2} }{4} - \frac{18 \sqrt{32} }{3} = \\ = \frac{3 \times 99 \sqrt{2} }{12} - \frac{4 \times 18 \sqrt{16 \times 2} }{12} = \\ = \frac{297 \sqrt{2} }{12} - \frac{72 \times \sqrt{16} \times \sqrt{2} }{12} = \frac{297 \sqrt{2} }{12} - \frac{72 \times 4 \sqrt{2} }{12} = \\ = \frac{297 \sqrt{2} }{12} - \frac{288 \sqrt{2} }{12} = \frac{9 \sqrt{2} }{12} = \frac{3 \sqrt{2} }{4}$

$f)( \frac{4 \sqrt{10} }{15} - \frac{ \sqrt{10} }{6} ) \div ( - \frac{ \sqrt{5} }{5} ) = \\ = ( \frac{2 \times 4 \sqrt{10} }{30} - \frac{5 \sqrt{10} }{30} ) \times ( - \frac{5}{ \sqrt{5} } ) = \\ = ( \frac{8 \sqrt{10} }{30} - \frac{5 \sqrt{10} }{30 } ) \times ( - \frac{5}{ \sqrt{5} } ) = \\ = \frac{3 \sqrt{10} }{ {30} } \times ( - \frac{5}{ \sqrt{5} } ) = \\ = - \frac{15 \sqrt{10} }{30 \sqrt{5} } = - \frac{ \sqrt{2} }{2}$

$h)6 \sqrt{ \frac{5}{2} } \times ( - \sqrt{ \frac{5}{18} } ) \times \frac{ \sqrt{27} }{15} = \\ = 6 \times \frac{ \sqrt{5} }{ \sqrt{2} } \times ( - \frac{ \sqrt{5} }{ \sqrt{18} } ) \times \frac{ \sqrt{9 \times 3} }{15} = \\ = \frac{6 \sqrt{5} }{ \sqrt{2} } \times ( - \frac{ \sqrt{5} }{3 \sqrt{2} } ) \times \frac{ 3 \sqrt{3} }{15} = \\ = \frac{6 \sqrt{5} \times \sqrt{5} }{ \sqrt{2} \times ( - 3 \sqrt{2}) } \times \frac{3 \sqrt{3} }{15} = \\ = \frac{6 \times 5}{ - 3 \times 2} \times \frac{3 \sqrt{3} }{15} = \\ = \frac{30}{ - 6} \times \frac{3 \sqrt{3} }{15} = \\ = \frac{90 \sqrt{3} }{ - 90} = - \sqrt{3}$