计算:(1) (4倍的根号6-3倍的根号2)÷2倍的根号2(2) (根号5+6)(3-根号5)(3) (根号x-2倍的根
2个回答

计算:

(1) (4倍的根号6-3倍的根号2)÷2倍的根号2

=4倍的根号6÷2根号2-3倍的根号2÷2倍的根号2

=2根号3-1.5

(2) (根号5+6)(3-根号5)

=3根号5-5+18-6根号5

=13-3根号5

(3) (根号x-2倍的根号y)(根号x+根号y)

=x-根号xy-2根号xy-2y

=x-2y-3根号xy

(4) 根号8-根号2(根号2+2)

=2根号2-2-2根号2

=-2

(5) 5倍的根号2+根号8-7倍的根号18

=5根号2+2根号2-21根号2

=-14根号2

(6) (根号11-根号10)(根号11+根号10)

=11-10

=1

(7) (2倍的根号3-3倍的根号2)的平方

=12-12根号6+18

=30-12根号6