观察下列各式:a+b=1,a^2+b^2=3,a^3+b^3=4,a^4+b^4=7,a^5+b^5=11...则a^10+b^10=?

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观察下列各式:a+b=1,a^2+b^2=3,a^3+b^3=4,a^4+b^4=7,a^5+b^5=11...则a^10+b^10=?
观察下列各式:a+b=1,a^2+b^2=3,a^3+b^3=4,a^4+b^4=7,a^5+b^5=11...则a^10+b^10=?

观察下列各式:a+b=1,a^2+b^2=3,a^3+b^3=4,a^4+b^4=7,a^5+b^5=11...则a^10+b^10=?
a+b=1
平方
a²+2ab+b²=1
所以2ab=1-3=-2
ab=-1
a^5+b^5=11
平方
a^10+2a^5b^5+b^10=121
所以原式=121-2(ab)^5=123