(√7+4√12)(√7-4√12) pake cara

[tex] = ( \sqrt{7} + 4 \sqrt{12} )( \sqrt{7} - 4 \sqrt{12} ) \\ = ( \sqrt{7} + 8 \sqrt{3} )( \sqrt{7} - 8 \sqrt{3} ) \\ = 7 - 8 \sqrt{21} + 8 \sqrt{21} - 64(3) \\ = 7 - 192 \\ = - 185[/tex]