（根号2-根号3)的2次方＋2倍根号3分之1X3倍根号2 =(√2-√3)²+2[√(1/3)]*3√2=2-2√2*√3+3+2[√(3)/3]*3√2=5-2√2*√3+2√3*√2=5
=2-2倍根6+3+2倍根3/3*3倍根2=5-2倍根6+2倍根6=5
