1.计算或化简
|根号2-根号3|+|根号3-2|+|2-根号5|
=根号3-根号2+(2-根号3)+(根号5-2)
=根号5-根号2
2.已知根号5X+2Y=4,根号5X—2Y=2.求X的平方-Y的平方的值
根号方程二边平方得:
5X+2Y=16
5X-2Y=4
解得:X=2,Y=3
X^2-Y^2=4-9=-5
1.计算或化简
|根号2-根号3|+|根号3-2|+|2-根号5|
=根号3-根号2+(2-根号3)+(根号5-2)
=根号5-根号2
2.已知根号5X+2Y=4,根号5X—2Y=2.求X的平方-Y的平方的值
根号方程二边平方得:
5X+2Y=16
5X-2Y=4
解得:X=2,Y=3
X^2-Y^2=4-9=-5