若x²-x-1=0,则x³-2x²-1的值等于___________.
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![若x²-x-1=0,则x³-2x²-1的值等于___________.](/uploads/image/z/603036-36-6.jpg?t=%E8%8B%A5x%26%23178%3B%EF%BC%8Dx%EF%BC%8D1%EF%BC%9D0%2C%E5%88%99x%26%23179%3B%EF%BC%8D2x%26%23178%3B%EF%BC%8D1%E7%9A%84%E5%80%BC%E7%AD%89%E4%BA%8E___________.)
若x²-x-1=0,则x³-2x²-1的值等于___________.
若x²-x-1=0,则x³-2x²-1的值等于___________.
若x²-x-1=0,则x³-2x²-1的值等于___________.
x²-x-1=0,所以x²-x=1 x- x²=-1
x³-2x²-1=x(x²-x)-x²-1=x- x²-1=-1-1=-2
-2
0