初二数学x²-5x-1=0 求x²+1/x²
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/11 20:41:44
![初二数学x²-5x-1=0 求x²+1/x²](/uploads/image/z/1635718-22-8.jpg?t=%E5%88%9D%E4%BA%8C%E6%95%B0%E5%AD%A6x%26%23178%3B-5x-1%3D0+%E6%B1%82x%26%23178%3B%2B1%2Fx%26%23178%3B)
x){1ɮgS7<]BMZ״B@&>eTO;lBS{9sɓK+Pkak Q
f"D3VF*i4E$AnTA]dǒv>l6["cqTϦ턈edku(VH=mm~ٚ/6<ٳɎ{OYtj==/? k
初二数学x²-5x-1=0 求x²+1/x²
初二数学x²-5x-1=0 求x²+1/x²
初二数学x²-5x-1=0 求x²+1/x²
x²-5x-1=0
除以x得 x-5-1/x=0
x-1/x=5
x²+1/x²
=(x-1/x)²+2
=5²+2
=27
x2-5x-1=0两边同时除以X
x-5-1/x=0
x-1/x=5两边平方
x2-2+1/x2=25
x2+1/x2=27
初二2元一次貌似不能用啊,那么。。。