Question

(1+√2)(1-√3)=(2-√5)²= (2√2-3√3)²=

3个题 在线等

Answer 1

(1+√2)(1-√3)
=1-√3+√2-√6
(2-√5)²
=4-4√5+5
=9-4√5
(2√2-3√3)²
=8-12√6+27
=35-12√6

(7+√7)²－(7－√7)²
=49+14√7+7-49+14√7-7
=28√7

( 3√2+2√3)(2√3-3√2)
=6√6-18+12-6√6
=-6

Answer 2

(1+√2)(1-√3)=1+√2-√3-√6
(2-√5)²=4-4√5+5=9-4√5
(2√2-3√3)²=(2√2)²-2(2√2)(3√3)+(3√3)²=8-12√6+27=35-12√6

Answer 3

(1+√2)(1-√3)
=1+√2-√3-√6

(2-√5)²
=4-4√5+5
=9-4√5

(2√2-3√3)²
=8-12√6+27
=35-12√6

追问

(7+√7)²－(7－√7)²=
( 3√2+2√3)(2√3-3√2)=
谢谢了

追答

(7+√7)²－(7－√7)²
=49+14√7+7-49+14√7-7
=28√7

( 3√2+2√3)(2√3-3√2)
=6√6-18+12-6√6
=-6

Answer 4

(1+√2)(1-√3)=1-√3+√2-√6；
(2-√5)²=4+5-4√5=9-4√5；
(2√2-3√3)²=8+27-12√6=35-12√6；

追问

(7+√7)²－(7－√7)²=
( 3√2+2√3)(2√3-3√2)=

追答

(7+√7)²－(7－√7)²=(7+√7+7-√7)(7+√7-7+√7)=14*2√7=28√7;
( 3√2+2√3)(2√3-3√2)=12-18=-6;