解方程 (4X^2+3)(4X^2+2)=12 5/X+1 — 10/X+10 =2/3X-3 6(X^2+1/X^2) +5(X+1/X=38
问题描述:
解方程 (4X^2+3)(4X^2+2)=12 5/X+1 — 10/X+10 =2/3X-3 6(X^2+1/X^2) +5(X+1/X=38
答
1、(4X^2+3)(4X^2+2)=12
化简得:8x^4+10x^2-3=0
因式分解(2x^2+3)(4x^2-1)=0
2x^2+3=00不成立
则:(4x^2-1)=0
x=1/2或-1/2
答
(4X^2+3)(4X^2+2)=12
16x^4+20x²-6=0
(2x²+3)(4x²-1)=0
4x²-1=0
x=1/2 x=-1/2
5/X+1 — 10/X+10 =2/3X-3
5/(x+1)-10/(x+10)=2/3(x-1)
15(x-1)(x+10)-30(x-1)(x+1)=2(x+10)(x+1)
15(x²+9x-10)-30(x²-1)=2(x²+11x+10)
-17x²+113x-140=0
17x²-113x+140=0
(17x-28)(x-5)=0
x=5 x=28/17
检验:
6(X^2+1/X^2) +5(X+1/X)=38
6(x+1/x)²+5(x+1/x)-50=0
[3(x+1/x)+10][2(x+1/x)-5]=0
3(x+1/x)+10=0 2(x+1/x)-5=0
x=-3 x=-1/3 x=2 x=1/2
检验: