Răspuns:
a)
[tex]3 \sqrt{18} = 3 \sqrt{2 \times {3}^{2} } = 9 \sqrt{2} [/tex]
[tex]2 \sqrt{72} = 2 \sqrt{2 \times 36} = 12 \sqrt{2} [/tex]
[tex]3 \sqrt{288} = 3 \sqrt{2 \times 144} = 36 \sqrt{2} [/tex]
[tex]5 \sqrt{1152} = 5 \sqrt{2 \times 576} = 80 \sqrt{2} [/tex]
[tex]7 \sqrt{648} = 7 \sqrt{2 \times 324} = 126 \sqrt{2} [/tex]
[tex]9 \sqrt{2} (12 \sqrt{2} - 36 \sqrt{2} + 80 \sqrt{2} - 126 \sqrt{2} ) = 9 \sqrt{2} \times ( - 70 \sqrt{2} ) = ( - 720)[/tex]
b)
[tex] \sqrt{50} = \sqrt{2 \times 25} = 5 \sqrt{2} [/tex]
[tex]4 \sqrt{243} = 4 \sqrt{3 \times 81} = 36 \sqrt{3} [/tex]
[tex]2 \sqrt{2028} = 2 \sqrt{3 \times 676} = 52 \sqrt{3} [/tex]
[tex] \sqrt{8} = \sqrt{2 \times 4} = 2 \sqrt{2} [/tex]
[tex]7 \sqrt{432} = 7 \sqrt{3 \times 144} = 84 \sqrt{3} [/tex]
[tex]3 \sqrt{3675} = 3 \sqrt{3 \times 1225} = 105 \sqrt{3} [/tex]
[tex]5 \sqrt{2} (36 \sqrt{3} - 52 \sqrt{3} ) - 2 \sqrt{2} (84 \sqrt{3} - 105 \sqrt{3}) = 5 \sqrt{2} \times ( - 16 \sqrt{3}) - 2 \sqrt{2}( - 21 \sqrt{3}) =( - 80 \sqrt{6} ) - ( - 42 \sqrt{6}) = ( - 38 \sqrt{6}) [/tex]
