Răspuns:
c)
[tex] \sqrt{6} \times \sqrt{5} - \sqrt{2} \times \sqrt{15} = \\ \sqrt{6 \times 5} - \sqrt{2 \times 15} = \\ \sqrt{30} - \sqrt{30} = 0[/tex]
d)
[tex]3 \sqrt{2} \times \sqrt{2} + \sqrt{2} \times \sqrt{18} = \\ 3 \times \sqrt{4} + \sqrt{36} = \\ 3 \times 2 + 6 = \\ 6 + 6 = 12[/tex]
e)
[tex] \sqrt{3} \times 5 \sqrt{5} - \sqrt{5} \times 3 \sqrt{3} = \\ 5 \sqrt{15} - 3 \sqrt{15} = \\ 2 \sqrt{15} [/tex]
f)
[tex]2 \sqrt{3} + ( - 4 \sqrt{3} ) \times 3 = \\ 2 \sqrt{3 } - 12 \sqrt{3} = - 10 \sqrt{3} [/tex]
