已知:x=根号5+1.(1)求x²的值.(2)x³-2x²-4x的值.
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已知:x=根号5+1.(1)求x²的值.(2)x³-2x²-4x的值.
已知:x=根号5+1.(1)求x²的值.(2)x³-2x²-4x的值.
已知:x=根号5+1.(1)求x²的值.(2)x³-2x²-4x的值.
x^2=(✓5+1)^2=6+2✓5
x^3-2x^2-4x
=x(x-1)^2-5x
=(✓5+1)×5-5✓5-5
=0