bentuk sederhana (2akar7 +6 akar 5) (3akar7-4akar5)

[tex](2 \sqrt{7} + 6 \sqrt{5} )(3 \sqrt{7} - 4 \sqrt{5} ) \\ = (2 \sqrt{7} )(3 \sqrt{7} ) + (2 \sqrt{7} )( - 4 \sqrt{5} ) + (6 \sqrt{5})(3 \sqrt{7} ) + (6 \sqrt{5} )( - 4 \sqrt{5} ) \\ = (6 \times 7 )+ ( - 8 \sqrt{35} ) + 18 \sqrt{35} + (24 \times 5) [/tex]
[tex]= 42 + 10 \sqrt{35} + 120 \\ = 162 + 10 \sqrt{35} [/tex]