Răspuns:
[tex] \sqrt{18} = \sqrt{ {3}^{2} \times 2} = 3 \sqrt{2} [/tex]
[tex] \sqrt{32} = \sqrt{ {2}^{5} } = 4 \sqrt{2} [/tex]
[tex] \sqrt{8} = \sqrt{ {2}^{3} } = 2 \sqrt{2} [/tex]
[tex] \sqrt{72} = \sqrt{ {2}^{3} \times {3}^{2} } = 6 \sqrt{2} [/tex]
[tex]3 \sqrt{2} - 12 \sqrt{2} + 4 \sqrt{2} + 6 \sqrt{2} = \sqrt{2} [/tex]
[tex] \sqrt{90} = \sqrt{ {3}^{2} \times 10} = 3 \sqrt{10} [/tex]
[tex] \sqrt{160} = \sqrt{16 \times 10} = 4 \sqrt{10} [/tex]
[tex] \sqrt{40} = \sqrt{ {2}^{3} \times 5 } = 2 \sqrt{10} [/tex]
[tex]12 \sqrt{10} - \sqrt{10} - (12 \sqrt{10} - 10 \sqrt{10} ) = 7 \sqrt{10 } [/tex]