若x+y=1,x²+y²=3,求x³+y³的值
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若x+y=1,x²+y²=3,求x³+y³的值
若x+y=1,x²+y²=3,求x³+y³的值
若x+y=1,x²+y²=3,求x³+y³的值
x+y=1
两边平方得
x²+2xy+y²=1
∵x²+y²=3
∴xy=-1
x³+y³
=(x+y)(x²-xy+y²)
=1×[3-(-1)]
=4