x²+1/x²
=(x²+2+1/x²)-2
=(x+1/x)²-2
=3²-2
=9-2
=7
x的4次方+1/x的4次方
=(x的4次方+2+1/x的4次方)-2
=(x²+1/x²)²-2
=7²-2
=49-2
=47
请点击下面的【选为满意回答】按钮.
x²+1/x²
=(x²+2+1/x²)-2
=(x+1/x)²-2
=3²-2
=9-2
=7
x的4次方+1/x的4次方
=(x的4次方+2+1/x的4次方)-2
=(x²+1/x²)²-2
=7²-2
=49-2
=47
请点击下面的【选为满意回答】按钮.