(1)根号1/3*根号12-根号75
=(根号3/3)*2倍根号3-5倍根号3
=2-5倍根号3
(2)2倍根号-根号3*1/2倍根号5除2倍根号20
=2倍根号3-根号3*1/2*1/4
=2倍根号3-根号3/8
=根号3*(2-1/8)
=15根号3/8
呃,最上面那位第一题错了。顺便答一下你后来问的。
(1)(2倍根号3-3倍根号2)(2倍根号3+3倍根号2)
=(2倍根号3)²-(3倍根号2)²
=4*3-9*2
=-6
(2)(1-2倍根号3)(1+2倍根号3)-(2倍根号3-1)的平方+2(根号5+根号3)
=1²-(2倍根号3)²-【(2倍根号3)²+1²-2*2倍根号3】+2倍根号5+2倍根号3
=1-4*3-【4*3+1-4倍根号3】+2倍根号5+2倍根号3
=1-12-12-1+4倍根号3+2倍根号5+2倍根号3
=-24+根号3(4+2)+2倍根号5
=-24+6倍根号3+2倍根号5
提醒一下,是-24,不是正的呃
:(1)根号1/3*根号12-根号75)
=1/3根号3×2根号3-5根号3
= -13/3根号3
(2)2倍根号3-根号3*1/2倍根号5除2倍根号20
=2根号3-根号3×1/2根号5÷4根号5
=2根号3-根号3×1/8
=15/8根号3
题目省了:(1)
=3分之根号3*2倍根号3-5倍根号3
=2-5倍根号3
(2)都一样:8分之15倍根号3
(1) 2/3倍根号 3
(2)15/8的根号三