(4+√3)^2 = 19+8√3 ,可液虚手得:x = 13/√(19+8√3) = 13/(4+√3) = 4-√3 ;
则有:x-4 = -√3 ,可得:(x-4)^2 = 3 ,
所誉扒以,x^2 = 8x-13 。闹嫌
(x^4-6x^3-2x^2+18x+23)/(x^2-8x+15)
= (x^2+2x-1) + (-20x+38)/(x^2-8x+15) 【这里是用长除法得到的结果】
= (8x-13+2x-1) + (-20x+38)/(8x-13-8x+15)
= (10x-14) + (-20x+38)/2
= 5
5