X加X份之1等于3 求4X加4X份之1等于?
问题描述：
X加X份之1等于3 求4X加4X份之1等于?
答
答案是12
答
x+1/x=3, 两边同除以4,得:x/4+1/4x=3/4
x²-3x+1=0
x=(3±√5)/2
4x+1/4x
=15x/4+(x/4+1/4x)
=15x/4+3/4
=(15x+3)/4
=(48±15√5)/4