How do you simplify (5sqrt2+3)(sqrt2-3)?

$1 - 12 \sqrt{2}$
$= 5 \cdot \sqrt{2} \cdot \sqrt{2} - 3 \cdot 5 \cdot \sqrt{2} + 3 \sqrt{2} - 3 \cdot 3$
$= 10 - 15 \sqrt{2} + 3 \sqrt{2} - 9$
$= 1 - 12 \sqrt{2}$