1)(a^2n+1·b^2n-1)^2·a^5·b^n= 2)a+b=15,ab=8,a^2+b^2=?

问题描述:

1)(a^2n+1·b^2n-1)^2·a^5·b^n= 2)a+b=15,ab=8,a^2+b^2=?

1)=a^(4n+7) * b^(5n-2)
2)a^2+b^2=(a+b)^2-2ab=15^2-2*8=209