a. 3√5 (2√3-3√5) =...... b.(7√2+√3) (7√2+√3)=...... c.(7√2-√3) (7√2+√3) =...... d.(7√2-√3) (7√2-√3) =...... tolong dijawab beserta caranya,karena besok mau diku

[tex]a. \: 3 \sqrt{5} (2 \sqrt{3} - 3 \sqrt{5}) = 6 \sqrt{15} - 9 \sqrt{25} = 6 \sqrt{15} - 45 \\ b. \: (7 \sqrt{2 } + \sqrt{3} )(7 \sqrt{2} + \sqrt{3} ) = 49 \sqrt{4} + 7 \sqrt{6} + 7 \sqrt{6 } + 3 = 98 + 14 \sqrt{6} + 3 = 101+ 14 \sqrt{6} \\ c. \: (7 \sqrt{2} - \sqrt{3})(7 \sqrt{2} + \sqrt{3} ) = 49 \sqrt{4} - 7 \sqrt{6} + 7 \sqrt{6} - 3 = 98 - 3 = 95 \\ d. \: (7 \sqrt{2} - \sqrt{3} )(7 \sqrt{2} - \sqrt{3}) = 49 \sqrt{4} - 7 \sqrt{6} - 7 \sqrt{6} + 3 = 98 - 14 \sqrt{6} + 3 = 101 - 14 \sqrt{6} [/tex]