Mg= √a×b
[tex] \sqrt{14 \times 42} = \sqrt{588} = 14 \sqrt{3} [/tex]
[tex] \sqrt{ \sqrt{7} \times 2 \sqrt{7} } = \sqrt{7 \times 2} = \sqrt{14} [/tex]
[tex] \sqrt{ \sqrt{20} \times \sqrt{45} } = \sqrt{ \sqrt{900} } = \sqrt{30} [/tex]
[tex] \sqrt{2 \sqrt{2} \times \sqrt{18} } = \sqrt{2 \sqrt{2} \times 3 \sqrt{2} } = \sqrt{2 \times 2 \times 3} = \sqrt{12} = 2 \sqrt{3} [/tex]