[tex]( - \sqrt{14} ) \times (4 \sqrt{7}) - (5 \sqrt{6} ) \times [/tex]
[tex] \times ( - \sqrt{3} ) = [/tex]
[tex] = ( - 4 \sqrt{14 \times 7} ) - ( - 5 \sqrt{6 \times 3} )[/tex]
[tex] = - 4 \sqrt{2 \times {7}^{2} } - ( - 5 \sqrt{2 \times {3}^{2} } ) = [/tex]
[tex] = - 4 \times 7 \sqrt{2} - ( - 5 \times 3 \sqrt{2} ) = [/tex]
[tex] = - 28 \sqrt{2} - ( - 15 \sqrt{2} ) = [/tex]
[tex] = - 28 \sqrt{2} + 15 \sqrt{2} [/tex]
[tex] = - 13 \sqrt{2} [/tex]
