[tex]( \sqrt{2} + 1)( \sqrt{2} - 1) = [/tex] tolong banu jawabsertakan dengan cara ya kak.. makasih

[tex]( \sqrt{2} + 1)( \sqrt{2} - 1) = 2 - \sqrt{2} + \sqrt{2} - 1 = 1

[tex]( \sqrt{2} + 1)( \sqrt{2} - 1) \\ = (\sqrt{2 } \times \sqrt{2} )( 1 \times - 1) \\ = 2 \times ( - 1) \\ = - 2[/tex]