1)令t=x+1/x, 则|t|>=2
则t^2-2=x^2+1/x^2
代入方程得:2(t^2-2)-3t=1
即2t^2-3t-5=0
(2t-5)(t+1)=0
t=5/2, -1(舍去)
所以x+1/x=5/2
x^2-5x/2+1=0
(x-2)(x-1/2)=0
x=2,1/2
2) 令t=(x^2+3)/x
则方程化为:t-4/t=3
t^2-3t-4=0
(t-4)(t+1)=0
t=4, -1
t=4时,x^2+3=4x, (x-3)(x-1)=0, 得:x=3, 1
t=-1时,x^2+3=-x, 无实根
故原方程的解为x=3, 1