x=√(5+2√6)
=√(3+2√6+2)
=√[(√3)²+2×√3×√2+(√2)²]
=√(√3+√2)²
=√3+√2
x=√(5+2√6)
x²=5+2√6
3x的平方-2x+4
=3(5+2√6)-2(√3+√2)+4
=15+6√6-2√3-2√2+4
=19+6√6-2√3-2√2���ܻ�����ô