Объяснение:

[tex] {(3 \sqrt[3]{7} )}^{3} = {3}^{3} \times { (\sqrt[3]{7}) }^{3} = 27 \times 7 = 189[/tex]

[tex] {f}^{l} (x) = 6x - 3 {x}^{2} \\ 6x - 3 {x}^{2} = 0 \\ - 3x(x - 6) = 0 \\ x = 0 \\ x = 6 \\ f( - 1) = 3 + 1 = 4 \\ f(0) = 0 \\ f(3) = 54 - 27 = 27 \\ max \: f(x) = f(3) = 27 \\ min \: f(x) = f(0) = 0 \\ 27 + 0 = 27[/tex]

[tex] \sqrt[5]{7 - \sqrt{17} } \times \sqrt[5]{ \sqrt{17} + 7 } = \sqrt[5]{(7 - \sqrt{17} )( \sqrt{17} + 7) } = \sqrt[5]{49 - 17} = \sqrt[5]{32} = 2[/tex]

[tex] \cos( {17}^{o} ) \cos( {43}^{o} ) - \sin( {17}^{o} ) \sin( {43}^{o} ) = \cos( {17}^{o} + {43}^{o} ) = \cos( {60}^{o} ) = \frac{1}{2} [/tex]