3（√2）+2（√3）分之√18-√12
=(√18-√12)/(3√2+2√3)
=(3√2-2√3)/(3√2+2√3)
=(3√2-2√3)²/[(3√2+2√3)(3√2-2√3)].分母有理化
=(18-12√6+12)/(18-12)
=(30-12√6)/6
=5-2√6