(1+根号2)²(1+根号3)²(1-根号2)²(1-根号3)²=(1+根号2)²(1-根号2)²(1+根号3)²(1-根号3)²=(1²-根号2²)²(1²-根号3²)²=(1-2)²(1-3)²=4
(1+根号2)²(1+根号3)²(1-根号2)²(1-根号3)²=[(1+√2﹚²×(1-√2﹚²][(1+√3﹚×﹙1-√3﹚²]=[(1+√2﹚×﹙1-√2﹚]²×[(1+√3﹚×﹙1-√3﹚]²=(1-2)²×(1-3)²=1×4=4