○ (a+b)(x+y+z) = ax+ay+az + bx+by+bz
○ (8+√3)(√3+9) = 8√3+8·9 + √3·√3+9√3 = 17√3+√9 = 17√3 + 75
○ (3√10+2√5)(√5-4√10) = 3√10 · √5 - 12·10+2·5-8√50 = 15√2-40√2 - 110 = -25√2 - 110
○ (-4√6-10√3)(√2-3) = -4√6·√2+12√6-10√3·√2+30√3 = -4√12 + 12√6 - 10√6 + 30√3 = 22√3 + 2√6
○ (6-√2)(3-5√2) = 6·3-6·5√2 - 3√2+5√2·√2 = 18-30√2-3√2+5·4 = 28-33√2