(3-根号2)的平方乘以(3+根号2)+(3+根号2)的平方乘以(3-根号2)

解
(3-√2)²(3+√2)+(3+√2)²×(3-√2)
=[(3-√2)(3+√2)](3-√2)+[(3+√2)(3-√2)](3+√2)
=(9-2)(3-√2)+(9-2)(3+√2)
=7(3-√2)+7(3+√2)
=21+21
=42
√6÷(√3+√2)+(√3+√2)÷√6
=√6(√3-√2)/(√3+√2)(√3-√2)+(√3+√2)×√6/(√6×√6)
=(3√2-2√3)/(3-2)+(3√2+2√3)/6
=(3√2-2√3)+(√2/2+√3/3)
=(7√2/2-5√3/3

(3-根号2)的平方乘以(3+根号2)+(3+根号2)的平方乘以(3-根号2)
等于7(3-根号2)+7(3+根号2)=42

30-4√2,先提取公因式