求值 解方程 (28 11:36:17)(1)1-根下2+根下3)*(1+根下2-根下3)    化简求值 (2)(根下3-1)*(根下3+1)x=4根下3-2(x+2)  解方程

问题描述:

求值 解方程 (28 11:36:17)
(1)1-根下2+根下3)*(1+根下2-根下3)    化简求值
 
(2)(根下3-1)*(根下3+1)x=4根下3-2(x+2)  解方程

很简单..

1.=1-(根下2-根下3)^2=1-(2+3-2*根下6)=-4+2根下6
2.(3-1)x=4根下3-2x-4
x=根下3-1

(1)原式=[1-(根号2-根号3)][1+(根号2-根号3)]
=1-(根号2-根号3)的平方
=1-5+2根号6
=4+2根号6
(3-1)x=4根号3-2x-4
4x=4根号3-4
x=根号3-4